Ah so the station is a terminal… like an end point. If you have more lines on that station, you might want to start the lines from the other end point and see what platform they chose at ur station with the issue. Am saying not to have all lines starting at one station… maybe that will change the platforms.
I have that “problem” as well sometimes which is why I always do my lines from one end station to another end station. At least then i can do something about the lines converging on a middle station and ease the waiting time.
Hope that makes sense…