Can't alter guest permissions in realms

In short: if I try to alter permissions for the other people in my realm, I get stuck in the menu. Clicking either of them just get me a select sound effect, and clicking the circle button to get out of said menu doesn't work, leaving me the only option of force-quitting the game and restart/relog to continue playing.

The reason I felt the need to do this was that one of my friends did get Minecraft so I could invite him to said realm and check it out. Unfortunately, though, just yesterday, I discovered that someone had apparently managed to start a realm with his account name, and when I entered it and asked what was up, I was mostly just met with silence, melee attacks and having the ground dug out underneath me. When I asked my friend about it, he basically told me it wasn't him, so if someone is accessing his account, I was planning on setting his name to visitor, so said person couldn't log on to my realm and create problems there. (For one thing, when whoever had managed to get into his account was playing, I noticed the icon he used back when we were playing on Xbox 360 together instead of his regular PS4 player avatar, and now both the names and avatars are listed on my member list.)