I've had this issue in 2 different local multiplayer worlds. Both times in both worlds (that i do not own) after I've signed out and signed back in all my things are gone including my map which is very frustrating. We've tried closing the world and going back in but I've never managed to get anything back. We're playing on beta on the Xbox 1s.
Same thing is happening to us. We're on Xbox 1s playing beta and any 2nd or 3rd player that joins any world cannot break blocks or pick things up, although it does look like the block breaks when they hit it. Also, if they attempt to break a block and then stand where that block was (and still is for player 1) they'll suffocate. We're in survival and have never changed to another mode.