I can't join my friend's world without it disconnecting me every 5 minutes. And she has to leave her world and go back in it before I can join.

For over a month now there has been a bug on Minecraft PE. I call it the multiplayer bug. It makes it so every 5 minutes after I join my friends world it disconnects me and she has to leave and join back into her world before I can join. I've been trying to deal with it but she made this new amazing survival world and I can't even play it for 5 minutes and it disconnects me. PLEASE FIX THIS!! I love Minecraft and I'd hate to have to delete it!