Ultrawide Resolution Bug -- Crash/Freeze Computer

As background, I play on a 3440x1440 ultrawide, that hasn't had issues before this. I just downloaded the patch. When I loaded into my first game, the resolution was initially set to 720p. I went to switch it, and automatically chose the highest resolution - which had previously always just been the highest supported resolution. This time it was 4K instead. The league client and window locked up, stuck on a black screen with only the cursor visible. I couldn't close the league client, and couldn't use task manager because it locked the entire window. On restarting, and trying to rejoin the game, the same thing happened. I changed the resolution back in the config file, but still had the same issue.

Aside from now having lost my first ranked game back, and leaving my team without the ability to remake, because apparently I was reconnecting behind the black screen, League is also now unplayable. Whenever I try and load a new game the same exact thing happens. Please fix this.