Purple to Purple SE Migration

TL;DR: it didn't (isn't) go(ing) well.

Set up using "Replace Old Box". Discovery initially went fine, but it got stuck at "Verifying Network Settings" and finally an "Internet Unavailable (10)" error pops up. Did this a couple of times before and followed the recommended actions for remediation (reboot modem, etc...). It then kicks you to Manual Setup as your only option.

I thought perhaps my NextDNS settings were interfering, so I went to my old box, removed DoH and the custom DNS settings for my WAN connection and tried again. Same problem.

At this point, if you try to setup the device using the giant + on the main screen, it won't recognize the QR code, but if you select/touch the box with a line through it icon (I guess this is "scan") on the top left of the app, it will allow you to go through a new setup or restore.

Restore didn't work, so I decided to set up as new, and then migrate settings. That worked, sort of. 

As other have noted, my devices didn't migrate into groups, and my IP range was different, so those static IP devices I had set-up in my network weren't showing up, and 80% of my devices (50 out of 62) weren't connected, presumably because they were all expecting the old IP subnet range.

I reverted back to my old FWP and re-enabled DoH (but didn't change the WAN DNS server addresses - left to the ISP default via DHCP). I've got to actually work, today, so I'm going to try again tomorrow or later tonight when no one is using the internet. I didn't expect to have this many problems.

Now, my Firewalla app on my iPhone is acting goofy. It's not connecting to my FWP. I just tried clearing the app cache on the app, I am about to select the OG FWP, but basically everything - settings, devices, etc - have disappeared (still showing on my iPad, though). Selected "Reset App Data", forced quit, and then it asked me for my e-mail address, to which I gladly supplied (again), but, the "Sign-up" button didn't work when pressed. It would just stay there.

Force quit the app and now we are back to square one, with both my FWP and FWPSE showing in the app.

So, what did I do wrong?