So at my house my internet is really, really bad, so I use cellular data all the time. I used to be able to invite my friends to my worlds on my cell data. This time I wanted to invite my friends, but the invite button was missing and the multiplayer thing was off, only I'm game. When I'm on my internet, it shows up, but I can't play because it's so slow. I've tried everything, and checked everything. I can play with my friends just fine, just not invite them. 

If this is on purpose, it is stupid and dumb, and your not the one paying for my data. I should choose how I want to play and what connection I want to play on. This isn't something for you to decide, it's for us to.