Apple TV 4K audio synch

My audio is out of sync when playing H.264 movies streamed from plex. I have a very fast pc w an i5 8600k, Nvidia RTX 3070, plenty of PSU, and the plex server is Lan wired to the Apple TV w cat 6e. The appletv plugs into tv using a heavy hdmi cable then a high quality optical cable to go from tv to a $450 Vizio sound bar.

The sound is usually about 100ms ahead of the video, sometimes more. Obnoxious.

I’m not entirely sure but I think DTS and Dolby play ok, audio synch error still there but is small. Still off some. So Dolby and dts still off some. I have a sound bar plugged into tv using optical, and hdmi goes from Apple TV to the tv.

sometimes the audio makes crackling sounds, maybe 2-3 times per movie.

yet.

netflix, YouTube, iTunes, prime all play w no crackles and no synch.

this audio synch issue has been a highly visible defect in apple’s product since at least 2020.

are you going to fix it? Or should we leave and switch to nvidia shield?

The old Apple created the first iPhone, and cut ground considered impossible. The new Apple can’t fix a real simple error, an issue using very common codecs????

has anyone figured out how to get Apple TV 4K to play movies correctly?