Hidden base directional tile on exit creates softlock.

[Colin Bechtel]

If you place a directional tile on an exit tile of your hidden base, when exiting you will step on that tile then, when you emerge from the pokemon center bookcase, you will go flying until you reach what I assume is the map boundary. You are then unable to move.

EDIT: Did not test this in all bases, so far only in mini forest with upward tile.