Terry Webbs hi Terry. I can confirm the first screenshot is exactly like my configuration.
About the second one: I don't have an ethernet but a Wifi, anyway I can still manually check the DNS settings in Advanced section and it's "correctly" (for my usage) set to 192.168.1.109 which is my PiHole IP address. The PiHole is also a DHCP. If/when I deactivate NextDNS, the hosts are being resolved by PiHole.
By the way I don't get how the network configuration is related to an app that is supposed to start at boot and it doesn't. Is it clear that I expect the app to open after login (like many other apps do: Docker, pCloud, PIA VPN, etc....) but it doesn't?
Probably no relation at all but it’s always a good idea to check to make sure the bare essentials are in place !
I had issues with the app second time round and my DNS wasn’t set correctly, may Mac was still holding on to an old DNS configuration.
The only other thing I can suggest you try is completely removing the app and any other associated files by manually searching for anything related to the app and removing it from all the library folders !