Closing as won't investigate: I don't see any evidence this is not just a mistake in your events. You need to keep the host and the peer all on the same layout at all times, and your events don't appear to be sufficient to ensure that happens. The multiplayer engine is also not designed to make people explicitly choose if they should be host or peer, it's automatically assigned and your events need to respect the automatic assignment, so I'm not sure what the purpose of having separate buttons for that is or what you expect it to do. It appears entirely possible that a user could click the "host" button and be automatically assigned as a peer or vice-versa, so I think you are just contradicting the way the multiplayer engine works.