There appear to be serious passenger behaviour issues on Arosa. Based on my testing of several morning timetable services (between 7am - 9am and 5pm - 6pm): There are zero passengers spawning at Arosa Station. It is a ghost town. Passengers never board the train (at any station, as far as I have observed so far). Version tested: Steam 4.26
Maybe they are mad that no train will ever meet its timetable since rivet has abandoned their plans for fixing the Arosa timetable, and instead stay at home or call an uber...