Confused about early/late trains in Thameslink 9 Dec timetable

The published B2 timetable (and the ones on station walls) show a mon-fri 23:42 departure from Brighton to Bedford. This allegedly arrives at St Pancras at 01:16. When I've turned up to catch this at STP it never shows and is not shown as cancelled. I notice that it apparently ran yesterday (Sunday/Monday). Does anyone know whether this is this a timetable error that should be marked as Sunday Only?

It is one of the overnight services that they are intending to re-start from January 7th. See https://www.thameslinkrailway.com/travel-information/plan-your-journey/timetables and then under the Winter timetable FAQs "
Why are 12 overnight Thameslink services not operating from Monday 10 December?"

I imagine that "To facilitate the smooth introduction of the winter timetable, and maximise the resilience of the daytime services in the first few weeks" means they don't have enough appropriately trained drivers...

Thanks @DaveN. That info was well hidden away - why they couldn't simply annotate the timetable(s) escapes me!