Schrödinger's Sonos
So I've wired in one of my Symfonisk speakers and this seems to have solved the issue of the speakers dropping out of the system (and disappearing on the Sonos App - but not the Spotify App??)
However my Sonos Roam, on a fixed IP keeps dropping in and out, and doesn't always appear on the Sonos App. However it DOES respond to Alexa voice commands...
