Hi @reckless derek.

Thanks for reaching out and welcome to the community!

I appreciate your detailed post outlining the issue as well as the resolutions you have tried, let me help and try to figure this out.

To isolate the issue, what is the audio source for HDR or 4K playback, is it just from the TV, or there’s a connected audio source on the TV (such as a cable box, Blu-ray player, or video game console)?

• Please check for firmware updates on both the TV and Sonos app. Install any available updates.
• Try adjusting the audio format on your TV to one of the audio formats supported by Sonos.
• You can find more details and suggestions on our support article about common fixes for TV audio interruptions while using Sonos home theater speakers.

If the above advice was followed and the issue persists, please submit a diagnostic report through the Sonos app when it happens, and reply with the confirmation number. I'd start by reviewing your system and see if there’s anything under the hood causing this issue.

Let us know how it goes and if you have any questions feel free to reach out, we’re always here to help.

Thank you Annazel - I have followed all of the above checks (the input source is the smart TV and the signal is showing as Dolby Digtial 5.1) all software is up to date and I have rebooted a number of times. Unfortunately this has had no effect and the problem persists. I will submit a diagnostics report to see fi you can detect anything. Thanks

Confirmation number is 2055018151

What happens if you use optical out and the optical to HDMI-ARC adapter?

This is just a troubleshooting experiment not a permanent recommendation

I would check the HDMI cables as 4k really pushes a lot of data. "Gold plated” is marketing BS. Make sure it can do at least 18Gbps. Needs to be HDMI 2.0 certified (ideally 2.1 to be future-proofed). Check both cables (source->TV and TV->Arc).

Could also be the TV of course. Almost no TV properly handles all of the modern HDMI signal types without firmware updates. If the TV is more than a year old, good luck getting a firmware update.

Thanks John B. I did try using the optical connection instead of HDMI as you advised but unfortunately that did not make any difference.

Thanks control av - the new HDMI cable is certified to the latest standard to take a 4K signal. So that is not the problem by the look of it . Interesting you raise the point about the TV being underpowered or on out of date firmware. The software level is up to date but I will dig a  bit into whether there is an additional firmware update available. Maybe the TV is just plain underpowered to process a 4K video signal and then convert and output to Dolby 5.1 through ARC?? It’s only a couple of years old so that would be pretty disappointing I guess. Still pinning my hope on the diagnostic sent to Sonos to avoid having to replace the Beam

Many thanks to @John B and @controlav for helping out.

Hi @reckless derek.

Thanks for your response and effort in submitting the diagnostic.

Upon pulling up the diagnostic report, there were no issues detected on your system at the time the diagnostic was triggered.

When I review the log information,  there’s an indication that the encoded signal has a discontinuity. Either it's corrupt or there is a legitimate change in the format of the audio.

Sonos speaker like Beam can only play what is handed to it, so I also suggest that it’s best to reach out with the TV manufacturer in order to identify what is causing these changes on the audio signal/format it is sending on the speaker.

If you have any questions, please feel free to let us know, we’re always here to help.