Hi @Mikepenny.

Thanks for reaching out and welcome to the community!

I appreciate your detailed post outlining the issue, let me help and try to figure it out.

Was there any change made before you notice this issue?

To verify, the Playbar is directly connected to the TV via optical cable?

How about the Humax PVR? How is it connected on the TV?

I suggest that we need to ensure that the TV was successfully programmed on the Sonos Playbar, to ensure that it is tied to the TV data.

Then, you may also try and adjust the audio format on your devices (TV and Humax PVR) to one of the following audio formats supported by Sonos.

Please note: The Playbar only supports IR remotes and will not work with Bluetooth, WiFi Direct, or RF-only remotes.

If that doesn’t help, kindly please submit a diagnostic report through the Sonos app, and reply with the confirmation number.

I'd like to see if there is anything under the hood that could cause this issue.

You may also check this article that contains guidelines for configuring your remote to control the speaker's volume.

Let us know how it goes and if you have any other questions or run into any issues, please do not hesitate to reach out.

Hi Annazel.

I have solved it!!

Seems that the hisense manual is wrong in saying that the ARC only relates to audio out on HDMI. Setting it to ARC first resolves the issue. Then why is there separate optical ot controls?. Most odd. But do appreciate your response and hope that this may help others in future.

Regrads

Mike