I tried playing the game with my cousin in my world (in Xbox One, created on 1.12.0) and he couldn't connect to it, and when I tried to enter in his world, that he just created at that moment (1.14.1), it worked.

It worked just one way, but not both ways.

We were in the same wifi.

Xbox One connecting to Android = Works
Android connecting to Xbox One = Doesn't Work