Apple TV 4K - Flashing White Grid

Every once in a while (no common keystrokes or apps used) the Apple TV 4K switches from what we were watching to a flashing white screen with a faint grey grid. The power stays on. Nothing will bring the Apple TV back to working except to pull out the plug, wait 15 seconds and the plugging it back it. It happened about twice a week. OS is updated. Not sure what is going on. Help, please.