My whole system is gone again...

I have no issues with my Galaxy S20 FE. Have you installed a desktop controller? If so, does it play music without issues?

@buzz ì can not test now because I reset my Beam+2xOneSL.

Now I have a new problem 😂 :

1. I see my Beam+2xOneSL (= Home Theater) in the App but not my 2 SONOS Roam…
2. I keep my 2 SONOS Roam ON and kill the app. I restart the app : I see my 2 SONOS Roam but not my Beam+2xOneSL anymore 🤣
3. I turn OFF my 2 SONOS Roam and… My Beam+2xOneSL is back and my 2 SONOS Roam disappear
4. If I turn ON my 2 SONOS Roam, they don't appear in the app

Is it the wifi 😂 ? Sorry but we know it’s a bug in the app!

Submit a diagnostic and post here and somebody from Sonos will hopefully come along and see it.

My guess is you have a kind of WiFi mesh system and some speakers are connected to one part and others to another. Within your own network they appear fine but your phone maybe only sees the ones that is is currently connected to.

@sjw Thanks. But no mesh and only one access point where all my device (with each an different IP) are on.

So you have an Access Point - which is a way of achieving what I described.  If you submit a diagnostic Sonos will see which devices are connected where.

I do think some work needs to happen on this kind of setup personally as AP’s and mesh systems are much more common now than they were not too long ago.

Supposedly even being on different channels can cause issues, never mind being connected on the same IP address range but one served by 2.4GHz and the other by 5GHz.

The user (for me) should not need to concern themselves about this - if they’re all on, for example, 192.168.1.XX then they ‘should’ work.

I’m sure ‘work’ may be involved from Sonos and other networking equipment manufacturers - but solving this would be in everyone’s interest - especially the users’.

Thanks @sjw I totally agree with you. I’m working in the WIFI “domain” and I know (I hope 😊) how all this hardware and protocols works.

No mesh at home today and all my SONOS devices are connected to 2.4GHz. My phone is on the 5Ghz, yes, but, like you say, that shouldn't be a problem : the discover process appear to “broadcast” on the 2 “types” (2 and 5GHz). And like I describe it, sometimes one appear, sometimes it’s the other despite my phone is always on the same wifi freq.

I tried to contact SONOS but as usual, nobody available…

I seem to remember having read in the last few days in this forum a concern similar to mine and that apparently, SONOS was aware of the problem of this user, that it was a bug on which they are working...

An interesting thing that I just discovered: when my 2 SONOS Roams are found (but not my “Beam2+2xOneSL”), I have my music list "My SONOS" and my playlists in the app. However, when my”Beam+2xOneSL” is found , the music list "My SONOS" is empty and my playlists have disappeared.

I have open another discussion because I think it’s not the same thing. the link : 

Do not Factory Reset any SONOS units without further consult.

That said, have you Factory Reset any units while you have been working on this problem? I suspect that you have and this can help explain the disappearing playlists.