I recently bought an LG 65" QNED86 (2024, WebOS) and have it connected via ethernet with no soundbar. Streaming apps such as TVNZ+, Prime and Netflix work flawlessly.
Then my flatmate purchased an AppleTV subscription and installed the app, and the problem is that the sound continually is dropping into a mode where we can't hear the voices. If we go into the sound option and change the sound mode to something else and back, the sound comes right for a while. But as soon as you press pause, or touch any other button on the remote, it drops back into an odd mode where we can't hear the voices. This could be any programme on AppleTV.
I'm a retired computer scientist and worked at TVNZ and Sky - I've checked for firmware updates for the LG and reinstalled the AppleTV app. I've checked that I have the "TV speakers" option selected. My opinion is that AppleTV have encoded 5.1 or 7.1 sound and that it's dropping into a sound mode where it's presenting rear audio channels through the TV speakers - there is sound, but it's not the stereo main dialogue through the TV speakers. And despite whatever sound mode I select, it drops back to this odd mode within a few minutes.
We've spoken to LG and after confirming the LG firmware was up to date, they say the problem is with AppleTV (since every other streaming app works flawlessly).
We've spoken to Apple, deleted and reloaded the AppleTV app, and finally they admitted they have other similar customer complaints and have offered to refund the subscription.
With some effort I could cobble together the optical output from the LG to a poxy 2.1 bedroom system to see whether the optical output has the same issue, but I'm not convinced this would be a definitive proof, and I wasn't planning on buying a soundbar.
(edit: if we access the AppleTV subscription on a computer, the sound is fine and does not have this problem.)
Does anyone have any suggestions? Otherwise it's goodbye to AppleTV...