(Thanks for the moderator edit to have combined my posts )

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.

Your system is obviously split in two.  It’s what happens when you factory reset units and then add them back incorrectly.  Check out your other thread for a solution.

And stop factory resetting your units unless told to.  It does nothing that a reboot will not do, and it erases important diagnostic info that Sonos support can use to get you fixed. 

@jgatie "factory resetting" like in the SONOS doc or like the SONOS support tell you to do because it's the "process" they follow?  if I could do otherwise, I would.  Unfortunately, this is the only way to overcome known bugs in SONOS systems (very poor wifi management, app bugs, etc.)

Could you explain me how we can "add them back  incorrectly"? Thanks.

No, it is not “the only way to overcome known bugs in SONOS systems”, I could give you a dozen ways to fix things without a factory reset.  As a matter of fact, Sonos itself tells you not to do it in a thread right here:

In addition, there are not any widespread “known bugs in Sonos systems”.  How do I know this?  Because there once was an actual bug in a singe Sonos device, the Playbar.  The main thread on that bug hit 100 pages in a few hours, and there were dozens of other smaller threads started. That’s what an actual bug looks like.

Now, if you split your system due to a factory reset, like you so obviously have, you will need to first remove any Sub/surrounds/stereo pairs you have in one of the split systems (the one you do not wish to keep), factory reset them, and then properly add them to the system you have left.  It will also help to reboot the other system to ensure they have an IP address which isn’t in use by another device.

Now, what say you?  Are you going to attempt to fix your system, or are we going to sit here and argue about this phantom “bug” of yours?

Android app has bugs : sometimes, the state (play, pause...) between my Roam and the app is not sync for example. Need to kill the app

You love SONOS. OK. Good for SONOS. We must not forget to keep a certain critical sense. Read updates made by SONOS. SONOS fix some bugs.

Factory resetting my system was first advised by the support I had on the phone regarding the problems I had installing Google Assistant (and that some still have...). So don't tell me it's not recommended by SONOS!

The behavior of SONOS positioning its products in the high end but not providing the service that goes with it is starting to tire me.  For example, you buy a soundbar and no surround sound!?  Why ?  SONOS justifies itself by telling you that only the sound coming from your TV and its installed apps are taken into account!  What about a Bluray player, game console, etc?  It would be good if SONOS had at least the courtesy to test and recommend a few products allowing the sound signal to be separated from HDMI, for example...

In the specific case of this concern, it is that the so-called easy use of SONOS products is not so easy!  We will say that there is the bug!

Your Android app ‘bugs’ are network issues, and not an issue with the app. 

I wouldn’t say @jgatie ‘loves’ Sonos, but I would suggest that he does have a rather substantial knowledge about how Sonos, and by extension, local networks work. I do not choose to ignore his suggestions, but try to learn from him.  We are all limited by what information is posted/ presented to us, so when we are wrong, the worst thing tends to be that we have eliminated one potential reason for what may be happening. 

From what I can read, you’ve closed your mind to possibilities, and have chosen to blame Sonos, rightly or wrongly, but unproven, for the issues you’re experiencing. 

Welp, I tried.  Let’s leave this one to their whining. 

Thank you very much for your attempts to help.

Before reset I tried all the methods (OFF/ON, search devices, reboot router , etc). I read a lot of posts here…

I've had SONOS for a few years now and the more time passes, the more I see the quality drop. I disassembled some (old models) to see what was inside. I isolated systems to listen and analyze the different network frames and protocols used. To be honest, I'm afraid of the new hardware that will soon be. The Roams are far from being of good quality (problems with battery, connection, sound...). The Android application is very far from being ergonomic. I also really like the steps to try to find your system, steps that end with "let's try again later..." rather than sending a report to support with a request for comment, for example.

I solved my problem last night and I confirm: there is a problem during the exchange of frames allowing the discovery of other elements of a system. But when I see the answers of some knowing people like @jgatie , I prefer to avoid making them lose the illusion that SONOS is a bug-free system .

Thanks again,

If you would elaborate on your findings maybe you could help Sonos.