Don't know if another topic has been made for this, but whenever I am playing with my friend in his world. Anytime we or myself place items such as workbenches, torches, chests, decor, etc, on either floors or walls, If I leave the area and come back, they all reappear under ground for me. On my friends screen since he is the host he does not have these issues. The good thing is that I can still access the chests from the original areas, but it makes it hard because they affect my movement when they are phased into the ground. Whenever we reset the game is a simple fix, but the moment i leave to do anything and come back, they all disappear again.