[GAMEPLAY] Unresponsive Cursor!

I haven't found a way to demonstrate this issue, but essentially, only DURING a game of League of Legends, my on screen cursor will not respond with the movements of my mouse. I tested my mouse repeatedly on other games, and just in general. This unresponsive behavior only occurs in a game of League of Legends and only since the most recent patch. I've also seen others complain about the same issue during matches, which leads me to believe this is a bug.