Problem to connect Sonos app on iPhone12

Ensure app permissions have been granted on your wife’s IPhone and try turning off “private address”

I’d also recommend until you can get one system working, you unplug all devices on the second system, just to reduce the potential variables. 
 

Which you do say you’ve done. That was for others who may come upon the thread. 
 

It might be helpful to have a better understanding of the way you’ve set it up, as well. What kind of router do you have? Is the system wired ( one device wired to the router ) or unwired ( all connecting to your WiFi)? 

@ClausN I’m not finding anything about how to toggle NFC and I’m not sure how to turn off private address. 

@Airgetlam I’m running on top of an Eero wifi system with 3 pucks (the router is Google Fiber), and 4 of my devices are hardwired -- 3 of them directly to an Eero puck, and the 4th is daisy-chained from a neighboring Sonos device. 2 others are operating off of wifi for a total of 6 S2 devices. To make things worse, my 3 remaining S1 pieces are not working properly whenever I bring them online. I may have to create a separate wifi network for them -- haven’t gone too far down that road yet because I’m focused on getting S2 to work right first. 

Several things there to comment on.

First, is the Eero set up as a bridge device, rather than its own router? You could be dealing with a double NAT situation, where both the Google fiber device and the Eero system are trying to give out IP addresses. 

Second, the Sonos device which is wired should only be connected to the root Eero ‘puck’, and no Sonos devices should be wired to the extension pucks. I suspect right now  each device is connected to a different subnet, if I recall how Eero deals with creating a mesh, which means they wouldn’t be able to see each other, or the controller. 

You’re absolutely correct to deal with one ‘system’ at a time, reducing all potential variables is always a huge help, making it easier to track and correct one issue at a time.

I’d recommend that you first set up the Eero as a bridge device, and let the Google Fiber router handle the IP assignments. Then, remove all Ethernet cables to the S2 Sonos speakers except one. That Ethernet cable would need to go to the ‘root’ Eero puck. Wait a couple of minutes, then fire up your S2 controller, and see if you can then see all S2 speakers. Which you should. 

Once you’re seeing all S2 devices, feel free to unplug them all from power, they’ll come back later when you plug them back in. At this point, connect a single S1 device to that base/root Eero puck, again using another Ethernet cable.  Plug all the S1 Sonos devices in to power, and wait another minute or two. Fire up the S1 controller, and double check that you can see all S1 devices in the controller. 

At this point, you should be able to plug back in the S2 devices, and all speakers should show up, in their respective controllers.