[Client] Stuck in "Match Accepted"

Sometimes when i accept a match, i get stuck at where it says "Match Accepted" and can't enter champion select. After champion select has ended for other players it says "User has declined ready check", which is wierd. In my newest case it then proceeded to put me in champion select after it acually had ended. Sometimes i manage to enter the game after champion banning has ended, but this does not always happen. The bug's occurence seems to be random, although i have a higher freqency than one of my friends.