Morning! Some drivers have indeed an issue where the stops on the Minimap are not showing up during a scheduled tour, as long as they have checked the complete map (by using the in-game pc) in CCS earlier.
-Short term solution (if OMSI has started already) is to select "show all stops" in the Minimap menu and then turn it off again. This may help to show at least the stops for your current trip. But the issue may arise in the next trip again.
-Long term solution for me was to not check the map screen during events by not going to the in-game pc (only use a bus from the company or ask CCS leader to rent a bus for you).
-Another option is to shortly leave the event, close CCS and OMSI completely, start it up again and then directly going to the bus without using the pc.
Hope this helps you further!
Best Regards, Mrbeans