There is a no-loss glitch doing the rounds (as I'm sure you've noticed) where the opponent disconnects when losing, and you get awarded a loss. If the opponent disconnects at any other time, the game just disappears from history, which wastes massive amounts of your time as you have to play 50 WL games instead of 30 to get 30 results.
I know it happens on PS4 and Xbox, but not sure if it's happening on PC.