Kings Cross Ticket Office refusing to sell walk-up ticket for 'sold out' GC Train

[LittleRedTrain]

I came across this post earlier from Paralympian and prominent rail accessibility advocate Tanni Grey-Thompson on X/Twitter:

https://x.com/Tanni_GT/status/1761104471738741132?s=20

I’ve booked assistance for a train. Go to ticket office. They CAN’T sell me a ticket because all the seats are gone in standard. I’m don’t need a seat. They can sell me a ticket for first class but there isn’t really a space in first.

Follow-up posts suggests that it was the ticket office at Kings Cross (so presumably staffed by LNER) and she wanted a ticket for a Grand Central train, but the ticket office was refusing to issue it because the train was 'sold out', even though she'd already booked a wheelchair space, so in essence, had a valid reservation!

My understanding was that ticket offices aren't required to book tickets against an itinerary, and so could sell any walk-up tickets even if the intended train was (falsely) claimed to be sold out.
Is this no longer the case, or was the member of staff concerned just poorly trained/informed?

Alternatively, is this a more insidious consequence of LNER's attempts to remove Off Peak fares and stop ticket office staff from being allowed to 'distort the market?'
Maybe a directive from on-high not to sell tickets without an itinerary?

Anyone have any further info/insight on this?

 

[furlong]

If it's Grand Central, so don't mess about with ticket offices for walk-up fares, especially if you've already got your reservation - simply pay on board! (Hope that "buy on board" message isn't getting drowned out by messaging from competitors pushing their own policies and ticket gates lacking sufficient prominent signage!)

 

[Dewedin]

Like the 'last train to Leeds' after the cup match next week where standard class reservations had run out, this is another case of LNER trying to overcharge a passenger by only offering a first class ticket. This false compulsory reservations nonsense needs to be brought to an end.