What could be causing the home screen app boxes to be scrambled as seen in this photo? This started happening the past couple of days. If I navigate away from the home screen and then go back everything displays ok for a while until the next time it happens. Nothing outside of the app boxes is affected as of yet. I'll try power cycling the Ultra to see if that helps. My Ultra 4640R is on firmware 8.0.1 build 4042.
A bad or improperly seated HDMI cable. Try replacing the cable or, sometimes a fix for HDMI cable problems can be accomplished by reversing the cable,
Two Roku Ultras, three Roku 3s and a Roku 1 "Part of the secret of success in life is to eat what you like and let the food fight it out inside." Mark Twain Van Roy's Law: An unbreakable toy is useful for breaking other toys.
After power cycling, the Ultra is still exhibiting the scrambled graphics and the problem has even spread beyond the app boxes with garbled graphics flashing in all areas of the screen. I'm guessing the graphics chip is failing so I'm packing it up for return.