I can’t turn on my multiplayer

I hope someone can help. Here’s my problem: when I am out of a game, I can access the settings and see that the multiplayer game is switched on but when I’m in the game, it says it’s switched off and is greyed out. How do I turn it on whilst in game? If I can’t, is there another thing I can do to turn it on so I can once again host a game for my friends to play in? I’m on mcpe.