Apple TV 4K (1rst Generation): Intermittent Audio Loss

I've purchased and use 5 Apple TV 4K (1rst Generation) devices. Two of them have the following problem.

When starting a new TV show or movie, there won't be any audio. The feature plays (video) but there's no audio. This happens with several different, unrelated apps: Netflix, Amazon Prime, HBO Max, Hulu, etc.

It happens infrequently and randomly, making it hard to reproduce.

When it happens, and you switch from the app, audio is clearly working from the device to the speaker (sound bar) as the "bloop, bleeps" from the main Apple TV user interface come through just fine (as do any sounds in the various apps' browse UIs). So, anyone suggesting this is an HDMI cable issue or other hardware issue causing the audio to be lost outright: I'm skeptical. Audio works just fine immediately afterward if I switch back to the main Apple TV UI. I've read several other posts on this forum relating to audio issues and none that I've found describe this specific issue (and so the solutions and hypothesized root problems don't match; this isn't an HDMI EDID issue). I've used several different TVs (with and without sound bars) and cables. Also, it's happened for sure on at least two different Apple TVs (of the 5 we have/use).

I work around the issue by simply exiting the app, re-launching it and restarting my feature. However, it often takes several such attempts (from 2 to 10) before it'll work. As such, it is frustrating and annoying and I'd love a fix.

Also: this has been happening for years now, the implication being that this has happened with much older versions of tvOS, up to and including the current latest version (as of January 1, 2022).

An interesting extra detail noticed today: using the HBO Max app, we started a feature (Harry Potter Reunion: Return to Hogwarts) which started with HBO Max adds/previews. Those played the audio just fine. Then it clearly switched streaming sources to the feature and when that happened, we lost the audio. Skipping forward or rewinding, pausing/unpausing doesn't bring the audio back. We have to exit the app entirely (not just switch from it) and relaunch it, then restart the program. We had to do this 3 times this today.

So, the problem seems to be with whatever software component (API) that's likely used by all apps to play a streamed audio/video (AV) stream. I wonder if some data packets come in out of order or are missed, at the beginning (that's just life with UDP and networks generally) that it's unable to "recover" as you later fast-forward/rewind, or just continue (presumably getting the later audio stream packets but unable to play them once the software gets in this glitchy, buggy state). That's my hypothesis.