I was playing with a friend in his realm server, cheats enabled, and we went and decided to find a stronghold, so we find it, jump in, and get to the End with no problem. We were just messing around in creative mode and killed the Ender Dragon, we went into the portal to get back to the Overworld, and while the credits were rolling, I accidentally closed the Minecraft PE app, and was disconnected from the realm.

Not sure if it affected him from me crashing as well, but he disconnected too. For him it only said he couldn't join the realm once, then after a few minutes he was able to get back into the realm, he owns it. Meanwhile I can't rejoin at all. He says that it doesn't say I join, but I leave even though I never joined. It does however list my name for a few seconds in the player list before it says I leave. It gets to the screen where it's purple, but it will not go past loading terrain while trying to connect, it doesn't even say "Cannot connect to Realm". It'll bring me back to the home screen of my phone. We have four people on this Realm and nobody else has this problem.