It's the ladder and only happens on a new game or if you save the game with it stored on the floor. Once it's in the upright position, or if you save the game with it in the upright, issue is resolved, even if you put it back on the ground. If you save the game with the ladder on the ground, exit then load the map again, issue returns until you use the ladder. I think there is a collision issue with the barn wall.