I would have to assume that it would be a thing with the route. The 7 is from a time when openBVE didn't exist, so this route would've had to have been run in BVE2 or BVE4, where it didn't matter which side the doors opened on, because it wasn't possible to see from the outside, and animated objects weren't a thing in BVE2 or BVE4, so you end up with the doors opening on the same side at every station, because it didn't really matter. Even today if in openBVE the train has no animated doors, it doesn't matter. You could try to modify the station code in the route file to open the doors on the correct side.
