I actually have been having the same problem (or fairly close to that problem) myself. After I queue up and begin the game, right after loading screen finishes, sometimes my game will freeze up on the beginning screen of the game starting. After that, there's literally no way to leave the game. It literally freezes your whole computer and you literally have to restart your whole device with the power button. Of course, how ranked queue is now, you lose LP if your team remakes, so I've lost about 40-60 LP so far in 1 day from, like, four leaves and gained (5) 10 minute leaver busters. It all began after the mini maint check today, or whatever it was, but overall, I just want this bug to be fixed, whether or not I get my LP back or the leaver busters removed, I want the game fixed.