Very odd bug but okay no worries! Just update us on it when you get a fix :) .. I turned off the mouse sensitivity and it stopped it but couldn't move my mouse anymore LOL, I didn't think it was an efficient move since we get chased in your games.
When I adjusted the mouse sense to 0.1 it kept turning but it was a slower turn but still unable to really focus. Hopefully that helps or points you to the right direction of troubleshooting.