This is one of my pet peeves about TRS19/22 (can't remember if it was a problem before that).
Are you sure they're not leaving at all?
Give it a while, and you should see that occasionally a passenger that got off the train will disappear.
I believe it's a bug in the base code that causes this (I think I've read that in several places), and custom interactive stations don't have control over the speed that they leave the station (again, I believe that to be the case).
It's something that should have been fixed a long time ago, but N3V are too busy making the game 'shiny' to bother with quality of life stuff.
I'd like to see the passengers that have disembarked leave the station much quicker.
Maybe a passenger every '
n' seconds, where we get to choose
n.
I'd be happy if it was a passenger every second, hard-coded.
It's quite frustrating to pull up a full platform with 7 or 8 carriages, and when you leave, the platform is still full (albeit with the people looking the other way).
If you weren't paying attention to the fading in and out of the passengers, you'd swear that all the people on the platform had just turned their back to the train in protest to the ridiculous price of the tickets!
Don't hold your breath for a fix.
N3V doesn't use Trainz.
But if the cabin muffle bug is anything to go by, you can expect it fixed in the next 3-5 years.