[CLIENT] Mouse sticks to top left corner of screen at end of game

I recently finished a ranked game and at the end of the game, the enemy team surrendered while we were attacking the enemy Nexus. They surrendered while I was typing a message to my team, and when the victory logo popped up, my mouse became stuck to the top left screen corner. And it wouldn't unstick until I used task manager to close both the in game client and the new beta client. My new client won't open now, but the legacy one can. I don't know if this is common or if I'm just unlucky.