You don't say what support had you try or what you've done so a start at the basics.

Power down ALL Sonos, your router and reboot the controller device.

Power up the router and let it stabilize.

Open the Controller App.

Power up your Sonos one at a time and see if they connect.

Why are you using the S1 app?

Because my speakers are all manufactured before 2020 s2 app says will nt work with it.

I have done all that, was on the phone with tech support for an tried the new app made me update one of my apeakers, did not connect down graded back to factory and tried now not responding, this was all under the techs guidelines on the phone. 

Unplug the Sonos you tried to move to S2.

Connect an Ethernet cable to one of the other Sonos and to your router.

See if that connects to your S1 controller.

That doesn’t make sense. Because according to the link below Play 1 speakers are Sonos App compatible. So what am I missing about your post?

https://support.sonos.com/en-us/article/sonos-app-version-compatibility
 

Certainly all of my PLAY:1 speakers are working under S2. 

Going back to your original post. You said they all show in system. Does that mean they all had a “tri-angle” showing in the app beside each indicating there was a problem? If not they were OK if you could see them in the App.

So please advise regarding the above. 

Hi ​@Kb8man 

Welcome to the Sonos Community!

I am sorry to hear of the trouble you’ve had with your “frozen” S1 system upgrading itself to S2 - this is an issue we are aware of and aim to fix soon.

I am also sorry to say that you were given incomplete advice from the support agent you spoke to, resulting in an apparently unsuccessful attempt to fix things, where in actual fact it was merely incomplete.

As things currently stand, you have 4x Play:1 devices online and running S2, and they will only be picked up by the S2 app, while the S1 app will only ask for you to install the S2 app. This is actually what we recommend that you do, and that you now just add and upgrade the 1 offline speaker to S2 and continue as is.

If you really want to have all 5 speakers on S1 - not recommended as some services and radio stations will, over time, become unavailable, if they are not already so - please read on.

To do so, however, you will have to repeat the downgrade process that you followed while on the phone with one speaker, with the other 4 speakers.

Once all 5 speakers have been downgraded to work with S1, the S1 app, when opened, will no longer request that you update either the speakers or the app without letting you continue, though further S1 updates may be needed once the speakers have been added to S1. I recommend that you uninstall the S2 app as soon as you have finished downgrading the speakers to S1.

If you get stuck at any part, please call back in, quoting your case number - I have added notes to the case to ensure that the next agent you speak to will understand where you are, and what the actual problem was.

I will leave feedback for the agent you spoke to.

I hope this helps, and apologies again.

Thank you for all the help and suggestions. If Iwill try to download the s2 app and go from there what I get here and on the web researching there is no good news about s2 app, 85 % say it sucks….. I personnal did not like the fell of the app but then again when I had it on did not use it very long, long enough for me to figue out it probably was not a good idea. As, all my speakers will not connect although I keep getting the msg to download s2…..