Sometimes adding the Sub last can be a pain. Try removing your surrounds, then add the Sub before you add the surrounds again. You may also need to connect the Sub to your router with a cable.

Yep. Tried all of that.  No dice.  It's the update required to the sub that I can't get past no matter what order, what's connected, etc.  The update fails every time,   usually from the fix it screen as the sub adds not registered cause it cant run the update.   

How about removing the app, restarting your phone then reinstalling the app?

Do you have a PC or Mac? Install the app from the Sonos Support website and try again?

Yep. Still nothing. Tried an android,  an ios and a pc.   

Maybe try a bit different fix? Go to your router’s DHCP Settings screen and assign every Sonos device a static/reserved IP address. Power down ALL Sonos devices. Reboot the router, clearing the DHCP assignments. Then power your Sonos back up so they can pick up their new (and stable) IP addresses.

Try the update after doing this and see if it works. If not Ethernet connect the Sub to your main router’s Ethernet ports and give it another go.

If this doesn’t work I’d call Support back and give them another shot. Have your previous notes available and you might even shoot them a fresh diagnostic before calling.

I can't chg my router as it's supplied by my isp and locked out to me.   

ISP got involved.  They separated the devices.  They can see the sub poll the Sonos server and the download starts.   Then it fails.  It's definitely the sonos server, software and or hardware.   Even level 2 can't figure out a fix. They blame my network which it's not.  

Perhaps try a different local network - you could even ‘temporarily’ use a mobile WiFi Hotspot just to complete any updates. If it works, then you can look closer at your own local network setup.

One of my SL 1’s started doing the same thing. Spent hours on tech. Same thing they claim my isp. No not really. I’ve de paired multiple sets all over my home moved them around reset up pairing all without an issue…..except for this one SL…. It has become a paper weight.   Would be great to hard wire it to another SL but nope….. 

You don’t wire Sonos devices to each other. You wire them to your router, if necessary. 

Yep  I tried that as well. It would not register that way as well.  

​@Dna757,

Perhaps try a different DNS in the Router settings. Maybe use the Google or Cloudflare public DNS servers as stated below:

Google: 

8.8.8.8/8.8.4.4

Cloudflare:

1.1.1.1/1.0.0.1

Thanks for the reply but no….. Im not gonna try and change DNS or public private server settings…. This is not on me. This is a Sonos product that is out of warranty and voila it fails with no recourse for the client….

Additionally, if one has to go take a deep dive into settings and such than there is a serious problem with what the engineers have developed for the masses…...