This pretty sounds strange.
1. Have you already tried to delete the corrupt doors and place new ones into your game?
2. Which type of door do you use? Can you make a screenhot of it, that we will know, which type of door has that bug? Have you tried another door type? Does this happen with every type of door?
3. Does this also happen, if you don’t connect the door to another door and only use the teleport command from an invisible floor switch or an invisible actor to get the hero teleported to the target door?