Since last patch my game window doesn't always open and I lose games because of this

After champ select the game window doesn't always open for me. The client stays with the text that there is currently a game, but I can't enter this. Even after restarting client it doesn't open. And then I wait a while to get a notification that the game already finished because my team remaked. I contacted Riot support and of course the only "fix" they give me is to use Hextech Repair Tool and hope it won't happen again. Great...