I don’t think I did anything weird. I’ve tried to set up MAAS twice (in the config as seen in the first picture in the original post) and I’ve had the exact same issue both times.
I followed the MAAS installation guide to the T (except that I set up different region and rack controllers).
This is the guide I followed: MAAS | How to install MAAS
My first post on this forum prompted me to re-install OSs on those controllers and start over with MAAS, but to no avail, which is why I created this post.