Power down all Sonos and router/wifi.

Power up the router and give it a minute to stabilize and deal with your other devices.

Power up the Beam, give it a minute and make sure it is showing the Ethernet connection active.

Check your "disable wifi" setting to insured wifi is enabled.

Power up the sub and surrounds.

Recheck your system to see how it is all connecting.

You might consider going all wifi, the load on your local connection is minimal and the App will give you connection information you might prefer to the antique network matrix.

It’s been a while since I viewed the Network Matrix as I’ve now switched to a fully wireless setup.

Previously, the surrounds/Sub would move between 2.4GHz when idle and 5GHz when in use. Is this potentially what you are seeing?

The 5GHz connection being the private network created between the Beam and the surrounds/sub.

I also thought WM:3 was reserved for only the Era products when bonded as surrounds.

Hi everyone. Quick update about this.

After doing a lot of checks and resets this is the only thing that worked for me:

Initial state:

1. Beam connected by cable with WiFi off
2. Mini and SLs properly identified by Beam in Sonos App (Android)
3. Just a single 5G WiFi network is configured in the Sonos App
4. Network matrix with all the cells in grey
5. Beam in WM:0 and the other devices in WM:3
6. My WiFi access point was detecting all the devices connected to it

At this stage I “just” turned WiFi on for Beam but kept it connected by cable:

1. SonosNet started working
2. All the devices stopped the connection to my WiFi AP
3. All the devices went into WM:0

Now the funny part:

1. Beam is in SONOSNET_MODE with LOCAL_SONOSNET, NO_PRIMARY
2. Sub Mini and SLs are in SONOSNET_MODE with LOCAL_SONOSNET, NO_PRIMARY as well
3. All of them are working in the SonosNet infra channel
4. The network matrix sometimes has all the cells in green but some other times the beam → devices are grey while the devices → beam are green

So, it was a great improvement. However, there are still some inconsistencies but no idea what they could be related to

The initial configuration is confusing because the Sub and surrounds bond to the private WIFI transmitted by the Beam. This is not SonosNet. I have always had my soundbar hardwired withe my Sub and surrounds bonded wirelessly. I have Era 100s for surrounds that work with no issues.

i would suggest no paying much attention to the matrix at this point for you home theater system.

Since you recently enabled WIFI on the Beam, do another full power down of everything: Sonos, router and phone.

Power on your router and allow it to fully boot. Then the Beam, Sub and surrounds, allowing each to fully boot  before powering up the next.  Power on your phone and test your system again.

Hope this helps.

OP confirms their devices switched to WM:0. Completing a further reboot of all Sonos devices, router and phone is not necessary.

After a week and two fully restarts (not intentional, I had 2 power outage last week...) this is my current situation
Beam: WM:0, SONOSNET_MODE, LOCAL_SONOSNET, NO_PRIMARY

SubMini: WM:0, SONOSNET_MODE, LOCAL_SONOSNET, NO_PRIMARY

One SLs: WM:0, SONOSNET_MODE, LOCAL_SONOSNET, NO_PRIMARY

Network matrix:

Beam → devices: Grey

Devices → Beam: Green

IMO there’s something odd with the new firmware

When the Beam is playing audio, there should be an “undefined” column showing the 3 surrounds/sub mini connections to the Beam. This evidences the 5GHz connection between them and the Beam.

See the network matrix i posted here:

That’s more or less my status. My concern wasn’t about that column, it is about the row. This is my current matrix:

The most at the right column is the undefined you mentioned. And it is fine because it is reflecting how the Sub and SLs are sending information to the Beam. They are in green. So, I’m happy.
However, in the first row if you realise I have 3 greys. Those are the traffic from Bean to the Sub and SLs. Those sometimes are green and some other in grey. And this is what is driving me crazy

I know that the whole system is working and I can play Atmos, 5.1, etc. with no problems (no micro cuts or any other issue). But that status and having NO_PRIMARY in the Beam Wireless Info is what puzzles me:

​@acuesta - As I mentioned above, when the HT setup is idle the surrounds/sub will fall back to a 2.4GHz connection.