In your new router settings, try changing your new wifi credentials (SSID/wifi name and password) back to those of your old wifi to fool your system into thinking it’s on the same old wifi network. You’d obviously need to reconnect your other devices (phone, printer, TV etc) if you do this.

If you factory reset all your Sonos you lost everything. (Note to other folks, Please don’t do that)

Go back to the “Initial Sonos Install” steps and set up a new system.

Make sure your router is set to Sonos compatible settings.

https://support.sonos.com/en-us/article/supported-wifi-modes-and-security-standards-for-sonos-products

Thanks but I don’t want to change everything just for the Sonos - everything else is working well 

Thanks have tried to set up initial Sonos install and it sets it up but still can’t move the Sonos away from the Ethernet as WiFi is not connecting.  How do you get any reply from Sonos? Been on hold for hour and half twice.