Confusion over ticket permits on Stansted/Gatwick Express

[duncan788]

Today I had a super off-peak day return train with any permitted route ticket from Brighton to Cambridge with a 16-25 railcard, costing £23.65.
Since I usually take Thameslink, I wanted to try taking Greater Anglia/Stansted express this time. After collecting the ticket, I sent a photo to Facebook asking if I could travel on stansted express with it. They replied saying it was not permitted.

However, when I got to London Liverpool Street station, I didn't want to wait as long for the next train. I thought I could go to Stansted Airport and change there. On Trainline it said the next train was a Greater Anglia service to the airport, but the platform display showed it as the Stansted Express which confused me - could I board that train or not?

I asked the first staff member I saw, explaining I wanted to change at the airport, and they said it would be okay and allowed me into the Barrier.But I was still unsure, so I also asked the guard on board who said it was not permitted. Then I asked another station staff member who also said no, but no one gave me a reason why.

I thought I would be allowed since I had an "any permits" return ticket. I even asked about taking the Gatwick Express and their social media said yes to that. So what is the difference between the Gatwick Express and Stansted Express services? Why would one accept my all permits ticket but the other requires me to buy an additional ticket?

As a rail fan ,I was so disappointed about the word “any permitted routed” , How many people will be confused if they doing different regulations on the network l!

 

[jfollows]

A Brighton-Cambridge super off-peak day return (https://www.brfares.com/!expert?orig=BTN&dest=CBG&rlc=YNG&period=20240401) is valid via Stansted Airport.

See previous discussion at https://www.railforums.co.uk/thread...lid-via-stansted-airport.253417/#post-6374191

”Any permitted” means according to the routeing guide at https://data.atoc.org/routeing-guide which determines this to be a valid route.

Map WA at https://data.atoc.org/routeing-maps explicitly shows the route via “Stansted Group” which includes Stansted Airport station as well as the direct route.

”Stansted Express” is just a name for a regular train service which is no longer “express” anyway and has no special ticketing rules.

Many railway staff, such as the guard you encountered, do not understand the routeing guide and its implications on ticket routeing validity, which is often why they can’t give you a reason for their invented rules.

EDIT The valid routes you can take for this ticket are:

• LB
• VB

then cross-London by underground or Thameslink, followed by

• KE
• WA

as shown on https://data.atoc.org/routeing-maps

 

[duncan788]

A Brighton-Cambridge super off-peak day return (https://www.brfares.com/!expert?orig=BTN&dest=CBG&rlc=YNG&period=20240401) is valid via Stansted Airport.

After reading your replies, I arrived in Cambridge this morning and immediately went to the ticket office to ask if I could take the Stansted Express with my ticket. At first, the ticket agent said no, as I expected. But when I asked why, he could not really explain. He just kept saying my train ticket was not valid, rambling that if I wanted to go to the airport with this ticket, I would have to buy an additional ticket from Cambridge to the airport. He claimed this was because the Brighton to Cambridge route does not pass through Stansted, but I pointed out that the train I had taken to get to Cambridge did go through Stansted, so it should be valid (this sounds crazy but I have a recording proving it). He struggled to explain why not, possibly seeing my English wasn't great, and asked what language I spoke, perhaps hoping to find someone who could convince me in my native tongue. Only after I insisted did he get his supervisor, who one look at my ticket and immediately said I could use it, telling the first agent something further. The agent then took my ticket to double check if it really was valid to Stansted Airport, coming back to confirm that yes, it was valid.

When I then tried to board a train return for Cambridge (not even the Stansted Express) to go to the airport, the guard checking tickets again said my ticket was not valid, telling me to take the Thameslink to Brighton instead and asking why I would even want to do this routing (as if it's any of his business as long as it's legal!). At that point the train was just about to depart with no time for me to get off, so begrudgingly he let me on this time but warned there would be no next time. He claimed that for this route, my destination would have to specifically be Stansted Airport printed on the ticket (I've never heard of such a rule - is that even legal to TOC?).

For example,a off peak ticket from Brighton to London Victoria can be valid via Hove , Southern even running the hove shuttle on it , I don’t believe I can’t do the same on stansted.

This is clearly my right as a passenger with a valid ticket.
I am so angry about this!

 

[KT550]

If you had just wanted to try out Greater Anglia or the Class 745, you could have taken the Stansted train to Bishop's Stortford and changed there
for the next Cambridge train.

It's only going off route into the airport station that would not be permitted with your ticket. (Edit: incorrect; see post #2 & #8).

An any permitted route ticket is good on Thameslink direct, Great Northern from King's Cross or Greater Anglia from Liverpool Steet.

 

[jfollows]

This is clearly my right as a passenger with a valid ticket.
I am so angry about this!

I'm sorry to hear your story and I sympathise with you.

The thing about this forum is that it's self-correcting: I'm reasonably sure that I'm right in what I posted but if I'm not someone else will correct me.

The problem with the railway is people get freedom to invent and implement rules by themselves, and nobody is around to correct them when they're wrong.

If you had just wanted to try out Greater Anglia or the Class 745, you could have taken the Stansted train to Bishop's Stortford and changed there
for the next Cambridge train.

It's only going off route into the airport station that would not be permitted with your ticket.

An any permitted route ticket is good on Thameslink direct, Great Northern from King's Cross or Greater Anglia from Liverpool Steet.

I'm happy to be corrected, as I've said, but going via Stansted Airport isn't off-route, it's a permitted route for a London-Cambridge ticket and - by extension - the Brighton-Cambridge ticket the original poster holds.

 

[RuddA]

When I bought Cardiff to Norwich tickets from Trainsplit a couple of years ago (a single ticket, no splits) the itinerary was Cardiff-Paddington-Liverpool St-Stansted Airport-Norwich. Therefore I thought going into and then out of Stansted Airport was fine.

 

[duncan788]

you could have taken the Stansted train to Bishop's Stortford and changed there
for the next Cambridge train.

Unfortunately, the guard intercepted me right as I boarded the train in Cambridge, and I nearly wasn't allowed to take that service from Cambridge to Bishop's Stortford at all.

 

[KT550]

I'm happy to be corrected, as I've said, but going via Stansted Airport isn't off-route, it's a permitted route for a London-Cambridge ticket and - by extension - the Brighton-Cambridge ticket the original poster holds.

My mistake; you're correct.
I'd wrongly assumed the diversion into the airport station was causing the problem.

Indeed the RailUK ticket selling website offers BTN-CBG with a change at Stansted apt. for that fare.

I've learned something for future trips to Cambridge.

 

[Watershed]

Unfortunately, the guard intercepted me right as I boarded the train in Cambridge, and I nearly wasn't allowed to take that service from Cambridge to Bishop's Stortford at all.

It's very disappointing - though not hugely surprising - that the guard and ticket office clerk's knowledge of ticket validity was so poor.

Cambridge to London has long been valid via either route and even if it weren't valid via Stansted Airport, as a minimum you'd be entitled to take a Stansted service as far as Elsenham (or in practice, Audley End as Cambridge-Stansted services don't call at Elsenham).

 

[yorkie]

Today I had a super off-peak day return train with any permitted route ticket from Brighton to Cambridge with a 16-25 railcard, costing £23.65.
Since I usually take Thameslink, I wanted to try taking Greater Anglia/Stansted express this time. After collecting the ticket, I sent a photo to Facebook asking if I could travel on stansted express with it. They replied saying it was not permitted.

Greater Anglia are wrong.

However, when I got to London Liverpool Street station, I didn't want to wait as long for the next train. I thought I could go to Stansted Airport and change there. On Trainline it said the next train was a Greater Anglia service to the airport, but the platform display showed it as the Stansted Express which confused me - could I board that train or not?

Stansted Express is a brand name for some services operated by Greater Anglia; they aren't very express, though.

I asked the first staff member I saw, explaining I wanted to change at the airport, and they said it would be okay and allowed me into the Barrier.

They were correct.

But I was still unsure, so I also asked the guard on board who said it was not permitted.

These trains don't have Guards, but whoever they were, they were incorrect.

Then I asked another station staff member who also said no, but no one gave me a reason why.

Also, incorrect.

Unfortunately incorrect information is rife in the rail industry.

I thought I would be allowed since I had an "any permits" return ticket.

It is a permitted route and it is allowed.

I even asked about taking the Gatwick Express and their social media said yes to that.

Again, correct.

So what is the difference between the Gatwick Express and Stansted Express services?

Both are brand names for services operated by GTR and Greater Anglia, respectively.

Both are not really 'express' in that they aren't particularly fast, but don't call at some stations which the respective companies other trains call at.

Neither trains are anything special.

Why would one accept my all permits ticket but the other requires me to buy an additional ticket?

Both these brands accept regular tickets; there is no need to buy additional tickets. This is just some nonsense made up by some rail staff.

As a rail fan ,I was so disappointed about the word “any permitted routed” , How many people will be confused if they doing different regulations on the network l!

You have been misled by unknowledgeable staff.

 

[Watershed]

These trains don't have Guards

I suppose it's possible the OP boarded a CrossCountry service, which would indeed have a guard.

Any of the Greater Anglia Cambridge-Stansted services that originate at Norwich would have a guard as far as Cambridge, but AFAIK they leave the train there and it continues without a second member of staff.

 

[redreni]

Interesting.

 

[duncan788]

I suppose it's possible the OP boarded a CrossCountry service, which would indeed have a guard.

I did board a Greater Anglia train. On that particular service, there was a staff member sitting in the rear cab of the last carriage. Before departing, they announced that they would be checking tickets and walking through the train from the rear.

You have been misled by unknowledgeable staff.

When I'm misinformed by staff, can I perceive it as GA officially violating customer rights, making them unlawful? Is it conceivable that GA would be collectively sued, akin to GTR being sued for overcharging on multiple brands?



Also, I don't find my route peculiar at all. I believe my route is quite reasonable when not rushed for time. Having paid a hefty price for my ticket, it's only natural to opt for the most comfortable service.

South of London: Southern daytime requires a transfer at Hove. Thameslink: Apart from decrypted first class, lacks Wi-Fi, charging, and seats are very uncomfortable. GX:when not rushed in London Underground , is both fast and the best option.

North of London: GN/TL seats are uncomfortable. Thus, GA is the more reasonable choice. Moreover, GA's express service is both fast and comfortable.

I fail to comprehend why this is so difficult for guard to understand. No one said we must only take direct trains on this ticket . Why subject ourselves to discomfort on uncomfortable seats after spending so much on train tickets?

 

[yorkie]

I did board a Greater Anglia train. On that particular service, there was a staff member sitting in the rear cab of the last carriage. Before departing, they announced that they would be checking tickets and walking through the train from the rear.

Probably a Revenue Protection Officer/Inspector; it's their job to understand which tickets are valid and which aren't, but some train companies provide insufficient training in this area, and do not implement sufficient safeguards to ensure competency.

When I'm misinformed by staff, can I perceive it as GA officially violating customer rights, making them unlawful?

If you are denied rights, this is unlawful, however actually do anything, if you are not actually out of pocket, is difficult.

If you intend to assert your rights, you should travel anyway, and - under duress - pay any additional or excess fare demanded. You can then seek a refund of the monies incorrectly charged.

Is it conceivable that GA would be collectively sued, akin to GTR being sued for overcharging on multiple brands?

A collective claim is conceivable in theory, but it is costly and time-consuming, so highly unlikely to happen.

A claim against GA on this basis could never be on anything like the same scale as the GTR case, as there are very few similarities.

Also, I don't find my route peculiar at all. I believe my route is quite reasonable when not rushed for time. Having paid a hefty price for my ticket, it's only natural to opt for the most comfortable service.

You are entitled to take this route and next time you should simply take the route; if you have a particular itinerary in mind, it may be worth booking that itinerary, which is evidence of a contract.

South of London: Southern daytime requires a transfer at Hove. Thameslink: Apart from decrypted first class, lacks Wi-Fi, charging, and seats are very uncomfortable. GX:when not rushed in London Underground , is both fast and the best option.

North of London: GN/TL seats are uncomfortable. Thus, GA is the more reasonable choice. Moreover, GA's express service is both fast and comfortable.

I fail to comprehend why this is so difficult for guard to understand. No one said we must only take direct trains on this ticket . Why subject ourselves to discomfort on uncomfortable seats after spending so much on train tickets?

I'm not going to try to comprehend what goes through the minds of such people. However, if the company provided adequate training, and put in place sufficient safeguards, the problem would not occur.

Unfortunately, companies like GA know they can get away with poor customer service, and have no interest in making such changes. Furthermore, there is no effective passenger watchdog, ombudsman or regulator who has the understanding, interest and clout to actually do anything about it either.

If you're on Twitter, feel free to tweet them, and let me know, and I will be happy to back you up. Not that this would achieve anything; most train companies just aren't bothered about this sort of thing.

 

[duncan788]

Unfortunately, companies like GA know they can get away with poor customer service, and have no interest in making such changes. Furthermore, there is no effective passenger watchdog, ombudsman or regulator who has the understanding, interest and clout to actually do anything about it either.

I don't entirely agree that this is solely due to inadequate training of the Revenue Protection Officers/Inspectors. Both the ticket office staff and the onboard Revenue Protection Officers/Inspectors informed me that for this route,

He claimed that for this route, my destination would have to specifically be Stansted Airport printed on the ticket (I've never heard of such a rule - is that even legal to TOC?).

My destination would have to specifically be Stansted Airport printed on the ticket. This may be simply the company policy they are instructed to follow.

If you're on Twitter, feel free to tweet them, and let me know, and I will be happy to back you up. Not that this would achieve anything; most train companies just aren't bothered about this sort of thing.

I'm unlikely to pursue that. At the moment, I only have a screenshot from this morning when I asked them on social media whether I could take this service, the audio recording from my inquiry at the ticket office. I don't believe these would be particularly effective evidence.

In the end, I was able to take this route through the "kindness" of the Revenue Protection Officer/Inspector, but I suspect many others will encounter similar situations and be wrongfully overcharged by the rail company in the future.

 

[MikeWM]

I suppose it's possible the OP boarded a CrossCountry service, which would indeed have a guard.

Any of the Greater Anglia Cambridge-Stansted services that originate at Norwich would have a guard as far as Cambridge, but AFAIK they leave the train there and it continues without a second member of staff.

I thought that is what was *supposed* to happen, and it is what RTT says happens, but in practice I've always seen a guard stay on, make announcements, check tickets, etc. between Stansted and Cambridge, ever since the service was joined together with the Cambridge-Norwich. (When it was a separate service, there was never a guard).

Unfortunate to hear that the ticket office staff at Cambridge were less helpful than usual in this case - they're usually excellent.

I'd add that I've done London to/from Cambridge via Stansted literally hundreds of times in the last 15 or so years, without incident. It is unquestionably valid and most staff seem to understand that. I suspect the OP has been a bit unlucky in the staff they encountered in this case.

 

[duncan788]

When I then tried to board a train return for Cambridge (not even the Stansted Express) to go to the airport, the guard checking tickets again

I need to remind you that GA messaged me this morning (edit:27/04) on social media saying that I can ride on any permitted route train except for the Stansted Express. So, when I boarded the train from Cambridge, which was a GA train (edit: at least it showed as GA on the platform display, not just Trainline), I didn't worry about it and that's why I didn't record any evidence on the train, but at least I saw that there is a video camera on his clothes.

If you intend to assert your rights, you should travel anyway, and - under duress - pay any additional or excess fare demanded. You can then seek a refund of the monies incorrectly charged.

How about I get misled by unknowledgeable staff and miss the train that I could have boarded on the platform? While I was not in a rush, the staff made me wait on the platform for at least 20 minutes and I had to ride on a slower train. Is it possible to receive some compensation for this delay?

 

[yorkie]

How about I get misled by unknowledgeable staff and miss the train that I could have boarded on the platform? While I was not in a rush, the staff made me wait on the platform for at least 20 minutes and I had to ride on a slower train. Is it possible to receive some compensation for this delay?

Potentially, yes.

What was your planned itinerary, and what was the actual itinerary followed in the event?

 

[duncan788]

What was your planned itinerary, and what was the actual itinerary followed in the event?

Planned itinerary: I will wake up early and board the nearest train departing to Brighton via London. I have to meet someone at a coffee shop in Cambridge and inform them about my arrival time. Once I depart from Brighton, they will drive to meet me. After the coffee, I will have enough time to visit the shopping centre and Cambridge University. I plan to return to London Liverpool Street via Greater Anglia train as it has better seating. If I have time, I will Break the Train Journey with off peak ticket to go to Stansted Airport Terminal, which I have never been to before. Finally, I will go somewhere else or return home and have dinner.

Actual itinerary:
1. board the Thameslink train at 08:28 morning at Brighton (arrive in Farringdon at 09:47)
RTT:https://www.realtimetrains.co.uk/service/gb-nr:P51832/2024-04-27/detailed

2. Then take the 09:53 Crossrail from Farringdon to London Liverpool Street (arrive at 09:55).
RTT:https://www.realtimetrains.co.uk/service/gb-nr:G80186/2024-04-27/detailed

3. Passing the Liverpool Street Barrier 5 minutes (10:05) Before the 10:10 GA express train to Stansted Airport was scheduled to depart
RTT:https://www.realtimetrains.co.uk/service/gb-nr:L18866/2024-04-27/detailed

However, when I got to London Liverpool Street station, I didn't want to wait as long for the next train.

Plan to visit Stansted Airport if no train to Cambridge upon arrival at 10:58 to save time. Notify another person if the arrival time changes.

The staff informed me that my ticket was not valid, so I had to wait on the platform near 20 minutes (18 minutes) for a slower train (10:28) to Cambridge North, And finally arrived at Cambridge at 11:58.

RTT:https://www.realtimetrains.co.uk/service/gb-nr:L19550/2024-04-27/detailed

On my return journey, I didn't want to face the issue of the barrier not opening since it may not open automatically as GA said it's not valid on the ticket and discuss it with the staff again, I felt tired. Therefore, I decided to take the next train to London.

Although I was not in a rush, I still got affected as I was "unable to visit" Stansted Airport Terminal and wasted time waiting for a slower train at Liverpool Street.

 

[redreni]

Sounds like the gateline staff at Stansted Airport believe (rightly or wrongly) that there is a restriction prohibiting break of journey when travelling from London to Cambridge via Stansted Airport.

I can see why they might want these restrictions to exist.

 

[Haywain]

Sounds like the gateline staff at Stansted Airport believe (rightly or wrongly) that there is a restriction prohibiting break of journey when travelling from London to Cambridge via Stansted Airport.

I can see why they might want these restrictions to exist.

It sounds like the gateline staff at Stansted Airport were not involved at all, and had no opportunity to pass judgement on the validity of the ticket.

 

[Sleepy]

I suppose it's possible the OP boarded a CrossCountry service, which would indeed have a guard.

Any of the Greater Anglia Cambridge-Stansted services that originate at Norwich would have a guard as far as Cambridge, but AFAIK they leave the train there and it continues without a second member of staff.

Norwich to Stansted Airport services do have a guard throughout the whole journey (although real time
trains incorrectly states they don't - GA do allow DOO operation south of Cambridge during disruption)

 

[Haywain]

The ticket is clearly valid for travel via Stansted Airport, as the first member of staff correctly stated. Whilst they should not be getting this wrong, I have to wonder why the OP continued to, seemingly, ask the same question of as many different railway staff as possible, especially after being given a very clear answer here.

 

[redreni]

It sounds like they gateline staff at Stansted Airport were not involved at all, and had no opportunity to pass judgement on the validity of the ticket.

Perhaps the OP could clarify? I may well have misunderstood.

I understand the OP planned to "visit Stansted airport" en route, rather than wait on the platform for the first available connection, which I take to mean passing out through the gateline and re-entering later to resume his journey towards Cambridge and was told by somebody that this was not allowed.

I can now see on re-reading that this happened at LST and was only after he had been denied boarding on the first Stansted Express train to depart LST. And, on being told he would not be allowed to break his journey at Stansted Airport and would have to wait on the platform, he then abandoned his plan to use the Stansted Express and took a slower train direct to Cambridge.

I don't know to what extent, if at all, this caused an overall delay in arriving at Cambridge. I do think if a passenger is entitled to break their journey but is wrongly told by TOC staff that they can't, they have not got what they paid for. The OP intended to visit Stansted Airport and was prevented.

I don't know what his rights are in this situation?

 

[cactustwirly]

Today I had a super off-peak day return train with any permitted route ticket from Brighton to Cambridge with a 16-25 railcard, costing £23.65.
Since I usually take Thameslink, I wanted to try taking Greater Anglia/Stansted express this time. After collecting the ticket, I sent a photo to Facebook asking if I could travel on stansted express with it. They replied saying it was not permitted.

However, when I got to London Liverpool Street station, I didn't want to wait as long for the next train. I thought I could go to Stansted Airport and change there. On Trainline it said the next train was a Greater Anglia service to the airport, but the platform display showed it as the Stansted Express which confused me - could I board that train or not?

I asked the first staff member I saw, explaining I wanted to change at the airport, and they said it would be okay and allowed me into the Barrier.But I was still unsure, so I also asked the guard on board who said it was not permitted. Then I asked another station staff member who also said no, but no one gave me a reason why.

I thought I would be allowed since I had an "any permits" return ticket. I even asked about taking the Gatwick Express and their social media said yes to that. So what is the difference between the Gatwick Express and Stansted Express services? Why would one accept my all permits ticket but the other requires me to buy an additional ticket?

As a rail fan ,I was so disappointed about the word “any permitted routed” , How many people will be confused if they doing different regulations on the network l!

If you're buying on the day, it's a good idea to use an app like the train line, you can set via points on the search. This will then produce an itinerary, which proves that your ticket is valid via a specific route.

 

[Haywain]

it's a good idea to use an app like the train line, you can set via points on the search.

Or Trainsplit (the forum version) which allows via points to be different on the outward and return journeys, with added time if required.

 

[yorkie]

Planned itinerary: I will wake up early and board the nearest train departing to Brighton via London. I have to meet someone at a coffee shop in Cambridge and inform them about my arrival time. Once I depart from Brighton, they will drive to meet me. After the coffee, I will have enough time to visit the shopping centre and Cambridge University. I plan to return to London Liverpool Street via Greater Anglia train as it has better seating. If I have time, I will Break the Train Journey with off peak ticket to go to Stansted Airport Terminal, which I have never been to before. Finally, I will go somewhere else or return home and have dinner.

Actual itinerary:
1. board the Thameslink train at 08:28 morning at Brighton (arrive in Farringdon at 09:47)
RTT:https://www.realtimetrains.co.uk/service/gb-nr:P51832/2024-04-27/detailed

2. Then take the 09:53 Crossrail from Farringdon to London Liverpool Street (arrive at 09:55).
RTT:https://www.realtimetrains.co.uk/service/gb-nr:G80186/2024-04-27/detailed

3. Passing the Liverpool Street Barrier 5 minutes (10:05) Before the 10:10 GA express train to Stansted Airport was scheduled to depart
RTT:https://www.realtimetrains.co.uk/service/gb-nr:L18866/2024-04-27/detailed


Plan to visit Stansted Airport if no train to Cambridge upon arrival at 10:58 to save time. Notify another person if the arrival time changes.

The staff informed me that my ticket was not valid, so I had to wait on the platform near 20 minutes (18 minutes) for a slower train (10:28) to Cambridge North, And finally arrived at Cambridge at 11:58.

Can you clarify your destination station and your planned vs actual arrival time there?

When we ask for an itinerary, we have in mind something like this:

Planner - Results - FastJP

fastjp.com

0839 Brighton - Farringdon (0956)​

1005 Farringdon - Liverpool St (1007)​

1025 Liverpool St - Stansted Airport (1111)​

1148 Stansted Airport - Cambridge (1219)​

You should certainly complain to Greater Anglia about the misinformation. As you weren't actually charged an additional/excess fare, you don't have any refund claim with GA. You may have an entitlement to delay compensation, if their misinformation caused you to be delayed by a qualifying length of time.

In any event, GA should be apologising, agreeing to put in place appropriate measures to avoid such misinformation being provided in future, and I would also expect some form of goodwill gesture and/or delay compensation, as appropriate.

However, actually getting anything out of GA may be difficult at the best of times; this thread is currently difficult to follow/understand, so I would advise writing to them in a manner that is well-structured, clear, and concise.

Providing an itinerary (in clear and easy to understand list/tabular format) showing your planned itinerary, versus your actual itinerary after misinformation was provided, this could be useful, along with a description of what happened.

I would ensure that all relevant information is provided clearly and concisely, and anything not directly relevant is not included.

At the end of the letter, I would state what outcomes you would like to see to resolve the matter.

If you'd like to post a draft of any such proposed letter here, someone may be prepared to proofread it for you.

Good luck!

 

[duncan788]

It sounds like they gateline staff at Stansted Airport were not involved at all, and had no opportunity to pass judgement on the validity of the ticket.

Yes, I don't wanna explain that again if the barrier does not open automatically.

I have to wonder why the OP continued to, seemingly, ask the same question of as many different railway staff as possible, especially after being given a very clear answer here.

I only go to the ticket office in Cambridge after receiving JFollows' confirmation here. The reason is that I would like to know why the staff at Liverpool Street is saying that my ticket is not valid when travelling via the airport. I believe that I have the right to board the express train at that time. Therefore, I still want to try boarding it when I return. If I don't do this, I won't have any proof in case I receive a penalty from GA.

I don't know what his rights are in this situation?

I didn't feel my rights were considered until more and more victims were affected by the same scam.

If you're buying on the day, it's a good idea to use an app like the train line, you can set via points on the search. This will then produce an itinerary, which proves that your ticket is valid via a specific route.

Good Idea but I won't do that, I am not obligated to disclose my plans to the inspector when facing ticket inspection; as long as my ticket is valid. Conversely, each inspector is equipped with an electronic device. Why not reverse the situation? Upon encountering a suspicious route or invalid ticket, they should immediately use their network-connected electronic device to conduct checks, just like what Jfollers' does in #2.
----
Although GTR has been sued for overcharging on tickets using multiple brands, they do have a clear branding strategy. Even on RTT and Trainline, it's clear.
Unlike this incident with GA, where platforms and displayed operators on RTT are different, causing confusion.
Even their social media accounts are the same. Their staff even misled me, only informing me that all GA trains on reasonable routes are acceptable, except for express ones. (This is even wrong)

Additionally, Gatwick Express announcements on platforms explicitly remind passengers to ensure they have a valid ticket, attempting to clarify that our tickets might not be valid on Gatwick Express. If a train is operated by Gatwick Express on a different band, at least the display on the platform will show it as (GX carriage). However, most of GA's trains do not make it clear.
GTR may charge more, but at least they don't attempt to deceive you. You can board any train you're allowed to. But this time, GA feels like outright deception to me. Saiding the ticket is all permit route but then denying access is much worse.

-------------
Also ,Is it legal in the UK to take a picture or video with the staff at the ticket office without their knowledge and upload it to the internet as evidence if something happens?

 

[Haywain]

Good Idea but I won't do that, I am not obligated to disclose my plans to the inspector when facing ticket inspection;

What is being suggested is that you validate your planned route in this way rather than asking multiple staff. Failing to do that means that you are having to disclose elements of your travel plans by asking multiple members of staff. There are ways of finding out what all of the permitted routes are for a ticket, but asking staff is rarely the best way of achieving that, and if you have the information in advance you willbe better equipped to challenge (or ignore, as appropriate) those who have incorrect knowledge of the subject.