Alright, so I've been having this bug since the release of the Public Beta Test. Whenever I load the game up, the top portion of grass / mushroom walls re-appear through the walls / floor above it.
This is what it looks like after reloading a save :
As you may have noticed, the top portion of the walls have respawned through the wall above it. Not sure what to do about this, it's infuriating