My game did not save

I just won a normal game with Kha'Zix , running electrocute. However, when I looked, the mission part "Win a game with a Domination or Resolve keystone" hadn't registered as completed. Then, when i looked in my match history to find a picture to post here, I could not find the game. I have tried restarting the match history, then the entire client, but that didn't work. Please help. I really don't want this to happen again.