Hm, you could try creating a second Box Collider that wraps your door (must be a bit thicker). It should be child component of the door itself, so that it moves the same way. Now create an Begin Overlap Event for it and plug it into the “Stop” of your timeline.
Currently i don’t have time to create this on my own, but in theory this should work x)
PS: I don’t know how to create the cubic behaviour though.