So that's three devices on one network, all on the latest version of the app.
One, the oldest, an iPhone 7 sees all my sonos stuff, the other two, a Pixel 7 and a 2021 ipad, see two different sets of the speakers.
Had a problem a year or so ago that was similar and thought I'd found the solution, seems that you can't have an ethernet connected sound bar and expect that to work. But now this.
The whole sonos experience is rapidly becoming rubbish and no longer recommendable