Bitstream audio lag on Xbox One X (but not for blu-rays)

I’m going through this on the Sonos support forum now. While I was running a couple of checks, I realised that I had it a little bit wrong here:

With bitstream, there is no audio lag when playing blu-rays and I do NOT tell the Xbox to allow the receiver to decode the audio.

There is audio lag when playing games with this setup.

If I tell the Xbox to allow the receiver to decode blu-ray audio and the audio is being output through HDMI, the audio plays but the blu-ray picture freezes. I don’t believe this is an issue with the tv or Sonos because i can still move through the pop-up
menus with the picture frozen in the background and the sound playing.

If I disable the HDMI audio and use the Xbox’s optical output directly, it works as per the previous (blu-rays fine, games lagging).

Thanks, I just tried the direct connection and it's exactly the same as when it's going through the TV, no difference at all.

Ok, this in some way is a good news, perhaps we know that the problem isn't in your TV at the moment, must be something in the sound processing with the Sonos Playbase, have you tried to contact Sonos support? or searched for info/news in their site?

There is any firmware update for the Sonos? I think you must investigate in this way at the moment.

Is it possible that your are processing the signal twice? First at the xbox then at the Sonos play base? (Not familiar with Sonos) The TV would act more of a pass through. If the signal is being processed twice it would cause a lag.

Have you tried to connect the console directly to your Sonos Playbase? as a test, because if a direct connection works well in every scenario and with every setting, maybe the problem is the TV in the middle.

I've just been doing a bit of research and this would make sense. I found a Sonos support page that
mentions that Sonos doesn't support DTS which would be why that option doesn't produce sound, and briefly mentions using bitstream. I think it would be reasonable to assume that the Sonos kit is processing the signal, especially as the lag doesn't exist when
I specifically tell the Xbox to allow the audio receiver to decode the sound for blu-rays (and therefore not do the job itself).

Sonos kit is pretty light on the settings as they like it to be "simple" to set up, but this means the only option if I want to have surround sound is to tell the Xbox to allow the audio receiver to decode all sounds (not just blu-ray). I don't suppose such
an option exists?