Apple TV audio dropouts

Just set up our new Apple TV 4K a couple weeks ago. Love it. But after a few days, I turned on the system and the audio was dropping out. I get audio for a few seconds, then nothing for a couple seconds, then audio, and this continues. 

I tried it with several Apple TV channels and on TV inputs not connected to the Apple TV. The dropouts come with everything on the Apple TV, including recordings, but nothing else. So, that’s where the problem is.

I restart the Apple TV via Settings and the audio dropouts are gone. They come back several days later. Restart again, and so on. So, restarting fixes it temporarily.

I saw I had the audio on Dolby Atmos (but with no HomePods or anything) so I switched it back to 5.1 digital. Made no difference.

The TV set is a 2017 LG OLED.

Any suggestions?