DNS resolution not working and Docker container unhealthy after recent update

Here's a weird turn of events:

  • I set Pi-Hole 's IP (2x) as the DNS server in the firewall/router settings
  • I tried reaching tesla.com and it predictably didn't work
  • on a hunch, I though I could try and update Gravity - that worked and afterwards, resolution started working again and the devices all can access things again like before. This is literally all I did to make things work again.
    (FWIW, I've been trying all kinds of things over the last 2 days, except simply updating gravity as I didn't see a link)

Does this make sense at all? Can I do anything to help to further provide info - in case this was some kind of weird combination of things that makes Pi-Hole (in Docker?) go bork? Or was one of the db's corrupted?