Its been working and now all of a sudden it’s stopped.
My system is fine. I can plug in my other Roku and XBOX Series X and stream the same exact 4k Atmos Netflix/HBO content w/o a problem.
I did a restart. Updates are fine.
Audio Mode is set to Auto
Streaming Audio Format is Auto
Digital Output Format is Auto
Do you have any of the "Volume modes" enabled? While playing a video press the * button to check.
Not that it matters, but the 3920 was a "Premiere" model, not an "Express" model.
I did a factory reset and it fixed it.