We use "Schedule sequences" for trains to have a long journey around the railway. This is where a train might leave one station, do 10 "laps" round the railway in each direction then go back to the original station. To do that you have to use schedule sequences, because any one section of track is visited more than once.
I don't know if this is a new feature - but we found that the train was being changed when one schedule changed to the next. Typically that happened in fiddle yards. There is a sequence setting to prevent that: select train "keep" in each successor schedule.