I was playing with a friend one night and everything was going fine until the next day where my friend could not join my game anymore it would tell her "unable to connect to world". She has tried to get in on her Nintendo, switch phone and Xbox and they all state the same thing. Both of our Nat types are open, we are both running version 1.12.  and our privacy settings are set to open. To this day she cannot join my world nor can I join any of her's. I play on xbox one.