Idk man, as I said, I tested it all the ways possible and I can't seem to be able to softlock the level, even if I'm out of the room for literally 5 minutes. There's LITERALLY no other trigger/script that destroys this specific "ending" trigger, so there's no possible way for it to despawn.
Update: https://drive.google.com/file/d/1lUtKjnrIXCvzLz38usNhb1d8DukZ3yIT/view?usp=shari...
To apply the patch just move all the files to your game folder (make sure it's the updated version)
LVL12 Was patched so the trigger now it's above ALL the level floor now, included the hallway. Its literally impossible for the player to skip the trigger and it worked again perfectly with me.