Basically, if scrolling up and down quickly with my MX Master mouse, sometimes Firefox (and I stress only firefox) stops responding to mousewheel inputs when the window is active. By this I mean that if another window is open and not fullscreen, and just hover over the firefox window and scroll, the webpage will scroll fine, however making firefox the active window stops it from working again. Restarting/reconnecting the mouse does not solve the problem. Restarting firefox also does not solve the problem. Disabling/removing plugins/addons has no effect. The only way I've found to fix it is by resetting firefox completely.