Here's a video showing editing a door works:
I THINK we are looking at a completely different issue here, it's not as settings are not saved, because they obviously are. The problem is everybody seems to use the 737, and on the front door, it calls for a certain kind of staircase (they one without a vehicle) and THIS ONE I think might not have an animation long enough to display small changes in the door's height you are doing.
It can be seen by looking at passengers: if you lower the door of, let's say, 20 cm, passengers feet WILL go lower through the staircase, it's just the staircase that didn't raise correctly, so the editor is fine, I need to check that particular stairs model too verify all its parameters are correct, and possibly extend the animation length, to be more precise.