Apple TV 4K screen goes black when watching Apple shows in Dolby Vision

i know this has been talked about, but not this specifically. I have an Apple TV 4K. Just in the last month or two, when I watched an Apple show (Slow Horses, etc) in Dolby Vision setting, the screen will go black for a few seconds. Continues thru show. Only when watching Apple shows. No other apps. When I switched to 4K sdr, problem fixed. I’m ok with watching this way but it bugs me! There are pluses and minuses to both regarding picture quality. I’ve rebooted, checked for updates, checked hdmi cables(yes, I have high speed ). Any ideas?

Thanks

[Re-Titled by Moderator]

Original Title: Apple TV 4