Hi @RodgerJ 

Thanks for your post!

When updating a system (or part of it) from S1 to S2, it’s important that the remaining S1 devices be reset and setup once more in the S1 app - this is to ensure that there are two Sonos “Households”, which keeps the systems separate.

It does look like this was already done, however, as your S1 and S2 systems are on separate Households.

I recommend, therefore, that you get in touch with our technical support team for some in-depth troubleshooting.

I hope this helps.

Technical support did resolve my problem. Thanks. - Disconnect all S2 equipment before telling S1 to do a system compatibility check and then follow instructions.

The initial problem was caused because S2 suggested that I upgrade the Gen 1 Play 5 to make it compatible. It would be better if the Sonos S2 developers wrote a few lines of script to ignore any non-compatible Sonos kit on the network.

The fix worked for 12-days, the same problem has re-occurred. I feel that the only satisfactory solution will be for S2 to reject unsupported equipment and vice-versa.
 

Sonos are simply dancing round this issue rather than producing an effective solution.

Incidentally, my S1 now thinks that it only controls my Arc and no longer sees my Play 5, Gen 1 speaker.

That certainly suggests some sort of network issue. Likely either wifi interference  or possibly a duplicate IP address concern. 

Hi @RodgerJ 

Sorry to hear the fix didn’t last. I can still only recommend that you get back in touch with our team, however.