None of my friends can join my worlds but I can join theirs with no problem.

I have basically tried everything. I have deleted and reinstalled the game, which caused me to lose all of my worlds, I have logged in and out of Xbox live, I even tried to make a new Xbox live account but my friends could still not join me. So, I came to the conclusion it must be the game itself. Considering the fact that I can join everybody's worlds but none of them can join mine. My games are always on multiplayer, I have tried turning it off and on. I have tried logging out and restarting the entire iPad but nothing has worked. This has been an issue for me for 6-7 months. I've checked the versions, they're all the same. Even my friends who use the same platform as me are incapable of joining me.
I have basically tried everything that I've found on your websites, google and so on. I've done hours of researching and now pretty much just hoping you can fix it for me