If you‘re talking about cab no. 2 (which you use if you return from Boele to Hagen): That‘s a preserved bug. Didn‘t work correctly in TSW 2020 either.
It's more of a signaling problem. That place is one of the few exceptions where PZB 155 does not work. I drive mainly this locomotive and honestly, there is nothing to complain about At least for me.
The signal works fine with other locos. That's why my theory is that the problem is with the loco and not the signal but, of course, it will take a dev to actually go and find exactly what is wrong. I can also tell you that this is not the only signal in this route that fails with the 155.
It‘s definitely cab no. 2 on the 155 that‘s causing this issue, it works fine with the Br 185. What do you mean by „this is not the only signal on this route that fails with the 155“? I never had any issues with PZB on the 155 besides the bugged cab no. 2.
It means exactly what I said. Had the same problem with more than one signal. If it is a problem with cab 2 in the 155 as you suggest, it makes a lot of sense.