The internet signal is fine as another speaker in the same room as the router works consistently well. When I switch the speakers it still doesn't work in the othe rroom away from the router so its not a speaker fault.
Best answer by Smilja
Sonos app for iOS or Android: From the More menu, tap Settings > Advanced Settings > Wireless Setup. On the Wireless Setup screen, click the button that says "Reset". Then click "Done" on the next screen.
b) If 'Auto channel' is enabled in your router, then disable it and set a specific channel, either 1, 6 or 11. Change also the SonosNet channel ('More --> Settings --> Advanced Settings --> SonosNet Channel') to either 1, 6 or 11. That means when e.g. SonosNet is set to channel 6, put your router on channel 1 (or vice versa). See also Reducing wireless interference.