Since I now have access to PrimeVideo, I've finally managed to sit down and start watching The Expanse (no spoilers please, only up to about S01E07), but for some reason, I get an occasional sound issue.

Speech becomes very muted but all other sound seems fine. Then today, speech was muted but also has a bad distortion to it as well.

This has occurred on a couple of other shows via PrimeVideo as well but seems to come right after about 10s, but with The Expanse, seems to be longer.

Any ideas ?

Running the app on Xbox One, connected to a HTIAB for sound via optical.  Is on wired connection, gigabit fiber.

I've not encountered this issue on any other streaming platform via the same setup.