It is frankly incredible how utterly crap the sonos app is. Even when it was working a couple of weeks ago it took minutes to get any of my sources to play and 10 sevonds even to change the volume (though the sound was great!). But now, when I wanted to use the speakers for something other than the TV, I started the app and it says no products found (even though I can see two products in front of me working with the tv) and "Go to system settings". (And what and where is my system by the way? I've only got speakers and a phone app). Pressing the system settings button takes me to "update network" and "set up a new system". The first doesn't apply as if I've not changed my router and the second, well I never had an old system as I've already pointed out.
I've tried rebooting my phone. I'm going to try switching the speakers off and on.