I've recently upgraded my 10 years old Lifestyle V30, to 650.
I decided to use 1 HDMI cable to my LG OLED65C7V, and then connecting both Apple TV4K + Xbox One X to the Bose system.
I started watching my first 4K movie on the Apple TV4K, efter I've finished setting up my Bose Lifestyle 650, including the Adaptiq calibration.
After 30 min. movie time, the screen went black, to grey to nothing. I restarted everything, nothing helped. I couldn't get the screen back on, with Apple TV as the source. So I went to bed ...
I've never had these issues before I plugged everything to the Bose system. It should be updated according to the Bose setup menu.
My LG TV is with latest firmware and the Apple TV4K is with tvOS14 beta 4.