I played some 2v2 competitive games with a friend, and a weird bug happened to me twice. When my friend (party leader) searched for a game, I would join a match (and he would appear as 'joining', in-game), but he joined a completely different one. When the game startup countdown ended, matchmaking automatically joined me to my friends match, completely leaving the other game with the other 2 enemy players. There was no problem with this at first, but after finishing that match, we could no longer queue up to matchmaking because i was banned for leaving the game. (10 minutes, which i asume is 15 minus the 5 I spent in-game).
Please help.
I didn't find the right solution from the Internet.