I cannot join my friends' world trough Xbox live

Me and my friend tried to play on his or my world this weekend, I got the invitation and then I accepted it. Then the game put me into a loading screen where it sais: "Connecting to multiplayer game". After a while it just stops connecting and it sais: "Unable to connect to world", note that my friend is playing on windows 10 and I'm playing on a mobile device (Samsung Galaxy 2016). Sometimes doesn't even show him that he's online on the friends tab or the invite tab. Please fix this.