Sorry I did not see this sooner. If this still is a problem, and if there is no other issue, such as being low on memory or something like another program running in the background, you can try resetting the hardware accelerator. In Google Chrome, go to Settings in the hamburger icon in the upper right corner of the screen, go to Advanced at the bottom, go to System, and find "Use hardware acceleration when available." Either switch it on and re-load or, more likely, switch it off and re-load then switch it on and re-load. There are good instructions online. I am sure that other browsers have something like this.