When a local co-op player leaves the game and subsequently tries to re-enter they are offered the push start on controller x to join. Upon pushing they are given the account selection menu. When they select an account it doesn't load them into the game and instead returns to single player with the game menu open. This doesn't occur when the game is first started up, local co-op works normally until log out, this triggers the bug upon a rejoin. Fixing this requires turning off all extra controllers and manually quitting and restarting Minecraft.