Sonos speakers no longer connecting to Sonos S1 App?

[g7jhp]

My Sonos speakers (Play 1 and Play 5) have just stopped connecting to my Sonos S1 app.

I've tried:

1) Rebooting WiFi
2) Deleted and reloaded the Sonos S1 app
3) Reset both speakers

They seem to go through each stage and then fail at the the end.

Any ideas would be apprediated?

Thanks.

[xof]

Temporarily hardwire to router then go thru setup process, unplug cable whilst still near the router to confirm successful setup, then move back to original location.