Interesting. So the reason nxdomain is in that list is because of this. So I don’t believe we can just remove it. That being said this is helpful for getting it fixed.
What I might do is try to reproduce it with alternate on coredns. Assuming I can I’ll submit a bug there. If they’re able to fix it then we can use it too. If not then when I get a chance I’ll look into it more.
I actually didn’t know about alternate though. I had thought the HA team wrote the code for fallback themselves, did not know it was a modified version of an existing external plugin. Good to know!
EDIT: btw, not trying to discourage you at all. If you can figure out how to fix it please submit a PR! Although the pr can’t just remove nxdomain from the list for the reason I linked above.