Multiplayer option grayed out

I am a mobile player, and when I create a world I turn on multiplayer option, but after creating world. I can't send invitation to my friend. And when I tried to edit world. Then I see the multiplayer option is grayed out means I can't turn on multiplayer option. And in Microsoft xbox i accept the option allow friends for multiplayer but it still doesn't work. I tried to sign out and sign in again. But my problem is still not solved. Please do something.