Just to be clear, are you talking about the ‘Windows Native’ app, downloaded directly from Sonos, or the Web app? What happens when you temporarily disable Bitdefender?
I think I’d call Sonos Support to discuss it. No one else seems to have reported this, although given the Windows app was essentially ‘frozen’ years ago, in favor of the mobile apps. But if you’re using the Web app….still, this may be a local issue.
When you speak directly to the Support staff, they have tools at their disposal that will allow them to give you advice specific to your network and Sonos system.
The windows native app downloaded directly from Sonos. When I disabled Bitdefender there was no change, the problem persisted.
Issue has been resolved. It appears to have been something to do with my antivirus (Bitdefender) and after completely shutting the AV down, rebooting the desktop and restarting the AV Sonos worked