I suppose another bug like this one: https://forums.dovetailgames.com/threads/question-about-a-german-signal.37985/#post-280399
TrainSim-Matt explained in an earlier thread, can't remember exactly what he said but basically something in the signalling system has gone wrong and the signals are just going "I don't know what to do, please ignore this" and the advice was to file a support ticket detailing the service/scenario and exactly where the signal is (incl route) so they can investigate.