Best answer by Ken_Griffiths
I would switch off your ISP provided routers WiFi, if you have not done that already... basically treat your router as a modem as far as practicable.
Then I would run a scan at your locality and see what channels are in use by your hubs and your neighbours WiFi. Use an app like wifiinfoview, or similar, to get that information.
Next I would cable a single Sonos device to your main google hub only... this will begin the start of SonosNet/'wired' mode. Power off your Sonos devices and bring them back online, one at a time.
Next, ensure your Sonos mobile controller is connected to your Google Hub WiFi signal and open the App, you should hopefully see all speakers. Now do these two things...
1. Set your SonosNet channel in Advanced Settings of the Sonos App to the 'least-used' channel in your locality.
2. Goto Advanced Settings/Wireless Setup and remove/reset you WiFi credentials, as these are not needed when running your devices in SonosNet/'wired' mode.
Hopefully everything will then be okay, at least until the Google hubs decide to auto-change their channels, but if that happens and causes any problems in the future then just try changing your SonosNet channel to fix things.
Hope that helps to get you up and running.?