I would try turning off the router and unplugging your speakers if possible, then turn on/plug them all in.  If you still have issues, I would create a diagnostic and contact Sonos support.

https://support.sonos.com/en-us/article/submit-diagnostics

Thanks Danny

I’ve just had another look and its all come back - I changed nothing so just put it down to one of those glitches ‍♀️. 
Regards

Alison

Hi, I am not tech saavy but have managed so far….we moved some Sonos equipment from another home to add to our current location….some items are newer than others.

At my one home, I used the gold color app and at the other location used the black app...don’t know why but it all worked.

One item I added quickly connected, no problem but a few others didn’t work...after awhile speakers that were original to the location and working fine stopped working...slowly the original speakers stopped working except one…….

I tried everything I read...unplugged.speakers...unplugged router...checked that app and my phone are on the same wifi….baffled because I can only use one speaker in another room…….

Any help for an old granny would be appreciated...