its most likely punching when going into another room haha.
It creates a temporary object that lacks persistency (a variable in GMS2 that keeps an object or room loaded if it is set to true) which is why the game crashes since the player looks for the punch object when loading into different rooms so that the hand can home back to the player. if that makes any sense lol.
I'm planning to scrap punching to replace it with a whole different mechanic tho lmao