To get around longstanding wireless issues, today we bought a Boost and switched everything over (with great pain!). We now have all speakers connected, and my own iPhone, iPad and 2 MacBooks all working.
Bizarrely my partner's iPhone and iPad refuse to find the existing Sonos devices. The app simply shows the 'you need to add at least one device' screen. I've tried deleting and reinstalling the app, 'reset' the controller, restarting the phone. Nothing works.
Any suggestions much appreciated as the household approval factor for Sonos is rapid falling this afternoon (and it was in jeopardy before!)
Best answer by Chris