I've noticed since beta one on the ATV4k that the audio has stearted curtting out regularly for about 3 seconds and about every 10-15 minutes. It started out being once in a while, now it's regularly across all streaming apps (netflix, amazon, disneynow, nickjr, plex).
Submitted a bug report on it awhile ago, haven't heard anything back.
I have too. See post right below this one. the audio drops are a little longer in the current beta but I see they now have it designated as a bug in the Release Notes. For anyone else posting, it helps to paste your bug report number in the posts. It gets more attention from the devs.
Edit: issue appears to be fixed with beta 5.