S1 no longer working

@Mykari,
Here is one suggestion to perhaps try (it’s a bit long-winded… ‘sorry’) …

Try following these steps carefully.. and take time to go through the list below. but please note they will ‘hopefully’ only work as long as you have NOT factory reset either of your two Sonos ‘Connects’ - if you have reset both, then the below will not work…

1. Ensure your computer (and any mobiles/tablets) WiFi connection are all definitely running on the eero WiFi  network and not connected to any other WiFi signal. Check the internet is working by opening a page in a web browser and then close that.
2. Power off and set aside both the ‘Boost’ and ‘Beam’
3. Cable one of your old ‘Connects’ to the main eero hub only and power it on.
4. Delete the (gold icon) S2 Sonos App (if installed) on your Mac and/or mobile devices (this is an important step). S2 App is not needed on any device.
5. Reset the (black icon) S1 Controller App on the PC and then reopen the App - agree to all things you see on screen - and choose to connect to "existing" sonos system when prompted or connect to system found on your network and ‘if asked’ to press button on the Connect then do that. Also sign into your Sonos account in the App. Whatever you do at this point do NOT choose the option to create a new system.
6. Hopefully you will now be able to see both your powered on ‘Connects’ in the S1 Sonos App. If all is well then move onto the next step…
7. Next factory reset your Sonos Boost - do NOT cable it to your network. When it’s LED is flashing green, in your S1 Sonos App on a mobile phone/tablet goto "Settings/System/Add Product" and add the Boost to your system. 
8. When Boost setup is complete, power off your two Sonos Connects and now uncable the Connect from your Eero Hub and close the S1 App on your MAC/Mobile device.
9. Now connect your ‘Sonos Boost’ to the eero main hub and power it on (if not on already)... let it settle and connect to the internet.
10. Power on your two Connects - let them settle for a few minutes and then open the S1 App on your mobile and Mac - the two ‘Connects’ should appear in the S1 App.. if all is still okay then continue to the next step…
11. Now factory reset your Sonos Beam and once again when it’s light is flashing Green…. in your S1 Sonos App on your phone/tablet goto "Settings/System/Add Product" and  add the Beam to your system. .. when that’s added everything should now be fully working and all you need do after that, is to add your music library to your S1 Controller on the Mac computer - I assume you know how to do that?