I'm following along with the tutorial, but my locked door tiles aren't being replaced by the open door tiles when unlocked with the key. The open door tile appears just in front of the locked door tile, which remains on the wall. When the two screens are set to the same Screen Type, and picking up the key triggers both rooms, the tile is replaced as it should. It's only when the Screen Types are different, that I have this issue. Any idea where I went wrong?