Hi @craigljh, thank you for reaching to the Sonos community and I appreciate you for bringing this to our attention. Let me help you out with this.

I'd like to ask some questions to isolate the issue so we can create a path towards resolution.

1. Do you use the Sonos app to control the volume or the TV remote?
2. How many controllers do you use to connect to your Sonos system? This is to check that the other device is not controlling the volume.
3. To isolate the issue, do you also hear the beep sound when you're playing music on your Sonos Beam?
4. Have you tried disconnecting the cable from your TV and your Sonos Beam then unplug them from the power to refresh the devices?

After checking the steps above and you're still having the same issue, please submit a diagnostic report to further check on this. Let us know the confirmation number.

Let us know how it goes. We'll wait for your reply.