Haven't been here for a while, as everything has been working swimmingly. Until I updated to the new 9.2 non-beta app and now I've lost all rooms bar the one with a hard-wired Playbar, with a Sub and two Play:1s as surounds. Everything else has vanished - two more Play:1s, a Sonos 1, and two Play:3s.
I've tried power cycling everything but to no avail. The lights on the speakers are steady white, seemingly indicating all OK but nothing showing in the app (iOS) or on the PC controller.
I've submitted a diagnostic 1006539121.