Entire system keeps disconnecting

Correct, it is just a modem.  Router is the Netgear MR70.  I’ve tried to complete the recommendations, bottom line the system is now working.  However I would like to get some additional info about the following:

1. With regards to one SSID, under Wireless Settings, I have an SSID 12345_Main which includes 2.4 and 5GHz channels.  This was my original SSID, and I had a separate SSID called 12345_2.4; I have now removed the 2.4 SSID.  When I went to “Customize WiFi Network in the Netgear desktop app, I don’t even see 12345_Main, but I went ahead and created a new 2.4 Ghz network called 12345, and a third network for 5Ghz called 12345_5G.  When I finally  reconnected , I connected to the new 2.4 network (12345) and finally everything connected.  But I now have 3 SSID’s and can’t figure out how to delete the original 12345_Main.
2. I could not find a band steering option, but google says you can try to disable “Enable AX”, which I did.
3. Also could not find Airtime Fairness, the only info I could find says that it may have been eliminated in a firmware update, but no idea if that means it’s a default on condition or default off.  
4. Otherwise I followed all the reboot, unplug, delete/re-install app and at this moment Sonos life looks good

Thank you for your assistance.  Any further comments on the above info are greatly welcomed!

 I wish I could split the 2.4 and 5 giving them the same SDID.  Xfinity does not allow that with their Gateway ( Modem/Router ).  Years ago they provided a gateway that broadcast a 2.4 & 5.  The 2.4 & 5 were part of the SSID name.  All I did was make sure the first part of the SSID name was the same.  So it appeared homeWiFi 2.4 & HomeWiFi 5 ( Fake SSID of course ).  With Xfinity now I’m stuck with Band Steering.

 Confused as to why your router is broadcasting 3 SSIDs.  Does it do WiFi 6??

Glad your Sonos is working!

According to this link the Netgear MR70 is a Dual Band Wi-Fi 6 Mesh (2.4Ghz and 5Ghz). The MR70 is the Router and the Satellites are designated as MS70.  

If the MR70 were a Tri-Band router you might see the following band combinations:

2.4Ghz, 5Ghz and 5Ghz 

or 

2.4Ghz, 5Ghz and 6Ghz

That said your 2.4Ghz and 5Ghz should have the same SSID. If you are seeing a 3rd SSID then you must have a Guest Network setup as well. There’s nothing wrong with having a Guest Network it’s just that Sonos will not connect to it.

The reason for having the same SSID for your primary 2.4Ghz and 5Ghz bands is to allow Sonos and other Wi-Fi capable devices select the best band for their needs.

MoPac - The MR70 does do WiFi6

AjTrek1 - The 3rd SSID is not a guest network.  The “3rd SSID” is actually the original one I had, before I added the new separate band SSID’s yesterday.  I see no way to delete the 3rd SSID.

 I think you have to factory reset the MR 70.  I’d look it up.

​@Joe_Mamma 

If you must factory reset your MR 70 to remove the 3rd SSID you’ll need to follow my previous instructions (i.e. unplug all Sonos etc) to get everything correct. That also means you’ll have to setup the same SSID’s that Sonos is currently using. Do not change the SSID’s for Sonos as that will cause major problems. 

​@Joe_Mamma 

I just thought of this…

That 3rd SSID could have been one set for IoT devices and/or parental controls. Just a guess🤔