Often when using the Sonos App on my iPhone app will say it cannot find the Sonos system. This happens (like just now) when I haven’t moved, nothing has changed, the app just loses connection with the system. Sonos’ pat response is to blame the Wi-Fi network, suggesting I reboot my router, this is despite everything else working fine and being able to access the Sonos system via Alexa and other interfaces. I have had this problem with 3 different Sonos systems and Wi-Fi networks. After some indeterminate period of time the app will connect again (usually having lost a few rooms that come back gradually). I wish Sonos would stop blaming everything except their own app and work out what causes this ongoing problem.