My up to date FF screen starts shaking, primarily using Youtube for awhile and then going somewhere else. It will still start shaking using various websites. It takes a PC reboot to stop it. It does not happen using Chrome. I have done the following with no change: 1. Fresh install 2.Turned off hardware accel. 3. cache clear refresh 4. All extensions off 5. Started in Safe mode. This lasted the longest but it eventually started shaking.

Something to note: My screen size randomly increases/top tab bar disappears when typing something. It's random but it's new like the shaking.