The latest info on fixing your completely gone system (you might have to take a look at your wifi router settings)

Thanks for your valuable comments ranash1995!

I have a mesh network which worked very well and without lag with the old S2 app.

It is true that the main router is the most performant, while the satellites are less.

This means that in order to use the new Sonos app one should buy more performant routers. It makes sense when looking at your findings.

My plan for this weekend is the following:

• setup a separate WIFI network, e.g. guest
• install the older S2 app via APK on an unused Android 
• setup a new sonos account 
• install 1 old Ikea speaker from scratch

After testing this config, I will update to the new Sonos app. I`m afraid it will also update the FW of the speaker so I will not be able to use it anymore with the old app. Sacrifices for the science….

I will compare the throughput, lagginess etc. as far as this is possible with just one speaker.

It did not work as expected …

I installed the old S2 on a  new phone on a separate network. Made an account from scratch. Then I wanted to add an IKEA symfonisk to the new (still empty) system . Didn´t let me, had to update to the new app.

Did that. And before I could react, all my loudspeakers in the house were infected with a new update. 

This app is very intrusive and aggressive!

And it created an Sonos WIFI network! How do I get rid of that?

Anyway, setting up a new system with a new user on a separte network did not succeed: the new app recognized the speaker, played a sound, but did not add it. I tried 5 times and after an hour and several resets I abandonned.

After numerous updates and resets I now have an old S2 and a new S2 app on different phones, both managing the same system. All loudspeakers are up to date. And everything seems still to work with the old S2 app. I was even able to add the Symfonisk with the new S2 app to my existing system.

In comparison, the new S2 app takes a bit longer to load graphics. But the incredible sluggish lagginess from the beginning seems to be gone. When it comes to control volume of grouped speakers you see/hear the difference: in the old S2 app the volume modification with the slider is in real-time, with the new S2 app you have a slight delay (~1 sec)

I´ll continue to compare both apps in the coming weeks...

PS: did not touch any of my network settings. So the new S2 app seems to have improved.

I was linked here from my original post, and appreciate the info.  I have an Eero mesh WiFi system, and thought this could be it, but I don’t have the “wi-fi isolation” option.  I do have “thread” turned on, which I’d think is similar to the end state.  Also, I have an entire Samsung Smart Things Smart Home set up, and all those pieces are talking to each other across my network just fine.  I do have 2 networks, but all the Sonos products (and my Android phone) are on the same network.  Besides, due to the latest firmware update, my Android app just crashes (based on this post, it appears that’s because Sonos hates people using their own music libraries instead of streaming music). 

This just keeps getting worse… Right now, it appears that I can only use my Sonos system if: 

1. I use the Windows app on my laptop (not very conducive to being mobile, but at least I can use my music library). 
2. I only stream music, and unplug/replug any speakers that I was using my music library on. 

Here an update:

One device still runs the old S2 app on Android,  no issues, maybe a bit more laggy than before the updates.

Another Android runs always the newest one, no issues. But a bit laggy.

Did not try local libraries