Sonos can have problems with Mesh Wi-Fi networks, I had similar issues with Google Wi-Fi. Are your Sonos devices connecting via Wi-Fi? I suggest that you try to connect one of your Sonos devices via an Ethernet cable as a test.
Thanks for the advice .. I’ll give it a try and revert
Bob
Well I’ve connected one speaker by ethernet cable and so far so good! Does that make sense? ie one hard wired speaker helps feed audio signal to the others??
Bob
Well I’ve connected one speaker by ethernet cable and so far so good! Does that make sense? ie one hard wired speaker helps feed audio signal to the others??
Bob
Hi Bob.
Your Sonos system detects when one device is connected to an Ethernet cable and then creates it's own mesh network. It's recommended to delete the wi-fi credentials within the Sonos App now so that devices only use the Sonos net mesh. Glad, your system is stable now. 
Thank you thank you UKMedia!
System works, is stable and hasn’t dropped off in a week
Be good if Sonos included this tip with every speaker … I‘ve got eight or nine sonos speakers and had never heard of a Sonos mesh until I read your advice
Again thank youi!
Bob
Be good if Sonos included this tip with every speaker … I
Sigh. At the outset this was the only way to operate Sonos. It was a major selling point: a self-extending mesh, dedicated to audio and kept away from other traffic. There are related patents galore.
Because it wasn’t always convenient to wire a player Sonos released Bridge, followed by Boost.
It was in large part because the competition would crow that “Sonos isn’t really wireless” that they eventually introduced the ability to connect directly to a user’s WiFi instead.
Maybe it would be possible to re-market the idea of a SONOS mesh because we now have many “wireless” products that require a “hub” that is wired.
