Actually this happens at any Android device. Sometimes, the itens multiply when the person who joined take a item from a chest, also, sometimes the world stop generating for the person who joined (or client, better saying). Like, the world stop generating for the client, then he have to quit and enter the server to then see this part of this world. It's happening in INFINITE WORLDS. I hope it gets fixed in 0.13.1 because I'm tired to see my sister quitting and joining again just to load the world....