When you connect it with an Ethernet cable, are you doing so to the ‘base’ Eero device, rather than one of the extenders?

Any chance you’re running any VPN, virus/Trojan protection, or ‘work profiles’ on your controller device?

I’m surprised that an Eero firmware update trashed the system, but dumb things can happen. Your SONOS unit or controller may have signed on as a Guest.

Refrain from SONOS Factory Reset without further consult. Usually, this simply causes extra work and, while there may be an accidental, temporary improvement, this is not not a permanent fix.

Describe your SONOS system for us. Is it wired or wireless? What else is on your network?

Check the Eero notes here:

Yes, the base Eero device. I’ve owned the Eero Pro system for 3 years. Only after a recent Eero update did the system start acting like this

The system is one machine, Play 5 Gen 2. Aside from that, other electronics are on the system (computer, phones, tvs). I also disabled (temporarily) the 5 GHz network in hopes that a single signal (2.4 GHz) would make it easy. Sonos machine still won’t connect

I disabled the 5 GHz band and it still won’t finish the connection

I just want to make sure you all understand. The Play 5 Gen 2 is literally getting to the final step of wireless connection (“connecting to your network”) and just won’t finish the connection. I’ve probably tried to do this 20 times now.

Cant you just temporarily hard-wire it to get through Setup?

The hardwire set up works, but then it won’t find nor connect via wireless. It’s as if I would have to leave it in via ethernet forever. 

Oh, so it sounds like the wireless card has died, which is not uncommon with those. Call Support.