Apple TV 4K latest version horrible static

I would recommend unplugging the power cable from the back of the AppleTV for about 2-3 minutes. Then plug it back in and double check both ends of the HDMI cable are firmly attached. Then power on the TV and re-test.

On thing you didn't mention is if you are using Wi-Fi or Ethernet and if you have restarted your router. If you are using WI-Fi it is possible the Apple TV may not be getting a strong Wi-Fi signal where it is located. You can check that with an app such as iStumbler, verify the Wi-Fi signal strength in the room where the ATV is physically located.

Also, please remember to unplug your router (yes even if EVERYTHING else is working okay) and re-plug it in and then re-test.

By the way, Wi-Fi is very reliable however if the router is not supplying a strong enough Wi-Fi signal to cover all of your home that can cause issues. However, as you are using Ethernet then that isn't an issue for you. This is informational only, I support 4 4K ATV's (all 4K devices) in my home and don't have any other the issues you are stating. In my family room, I have a small Home Theater setup where I route that ATV through my receiver to the TV. The others are connected ATV - TV direct.

Don't need no fiber optic 8K premium mumbo jumbo marketed super long ultra stuff. That's only for wallet-emptying. Just a well-insulated short HDMI cable will work fine. 6 feet is inviting trouble. Reduce to 3 or less.

Audio with the Apple TV has been an issue forever and I’ve seen suggestions dating back to 2010. I’m 71 and not in the mood to try 20 different solutions. However I did want to add that I just switched to my roku stick (watching season two of the house of dragons) and magically the audio is sooooo much better. My kids use their Xbox and won’t use Apple TV. I’m going keep using the Roku stick and see if it improves on all the apps. Netflix has become an issue to. The only other thing I might try switching the HDMI for Apple TV and Roku. If somebody wants to add to this without getting too technical or some of my age, please feel free to do so

+1 to @Kaufmann. If any of the HDMI cables are longer than 3 feet (1m), I would replace with shorter.

Those HDMI cables look awfully long to me - anything over 3 feet, doesn’t matter what the packaging boasts, is IMO inviting trouble.

Lots of mumbo jumbo ultra HD marketing on the package, but yes 0.5m and 1m are good. If you can find similar without the packaging BS and without fiber optic over kill, even better.

Doing it 1x should do the trick, however if the problem comes up again now you know what to do.