Happens to me almost all the time, usually I'm in one lobby and I can leave, then I go into another lobby and when I decide to leave that one, it just sits there and "freezes"... its annoying. If you quit the game, your save data will be fine, so don't worry about that. I found though that if I clear my cache before I go online, it doesn't freeze as much. Its been happening to a lot of people though, so I'm 99 percent sure its because of update 1.10.