On this service you get stuck at a red signal 1.7 miles out of Brighton because there's a train on Platform 3 that isn't supposed to be there.
Yes I have encountered this problem on 1w78 (Ps4) Just north of Preston Park. Backed up trains all the way to Brighton.
Still broken on XSX after today's patches… There's a 'Not in Service' 387 at Brighton Platform 3, that you cannot take over. This may also affect the following services (all of them were stuck at a red): 1A30, 1W74, 5A43, 5U83, 1A28, 5U29… (Edit: filed a bug report)