ios 26.4.1 has broken S1 app?

Try removing and reinstalling the app, joining an existing system when prompted.

I’m quite experienced with our Sonos system and have tried everything I can think of. The error message I get is that I have to update my system and re authorise the apps eg BBC Sounds ie to S2. We have a considerable investment in S1 Connect:Amps etc and am in no hurry to junk them. 

There have been a couple of threads here recently where other S1 users had similar issue. Good luck trying to find them though as the search on this forum mostly useless.  I can’t remember the solution, other than the standard contact Sonos Support.

And it is not possible to update the system and reauthorise the music services?