If you skip talking to caroline in the stairs room, and just go straight through the door, the room loops, but this time the bookcase won't move, because it has already moved so it just says "it moved on its own" when you interact with it. You cannot go back through the entrance door.
Not sure if this soft lock is intentional or not haha, but it seems to be a thing, unless I just can't figure my way through it and it isn't a softlock at all