Minecraft PE Friend Invite Is Grayed Out?

What should I do I wanted to play mcpe a friend and he wanted to invite me but it is auskraut with him. PS: The (Invite friend) is weeding.

Maybe you do not have internet or if you are not connected to Xbox live…

But my buddy is logged in to Xbox Live has also Internet but no Wi-Fi connection but he's set in the settings to use mobile data and in Ines is just greyed out