Chatroom bug in client

Hi, every time I log onto the League of Legends client I join the "Pool Party" chat room and every time I immediately close the chat room (because Pool Party ended months ago lol). I'm wondering if I'm doing something wrong and if there is a different way to permanently exit the chat room, but I'm more inclined to believe this is a bug. This has not happened for any other chat rooms I've entered and left.