After a bit more experimenting, I found out that this issue is not specific to Miraheze and occurs on Gamepedia as well under certain circumstances.

Thank you, it's working great!

Here it is

google-site-verification=07tDAfwRr6KvnZRzcIdMCm7dfyJm9pOSRVMpxPxZxqM

As everything seems to be working alright, I don't see much of a reason to switch at the moment.

Well, either way is fine with me. Just go with whatever is easiest for you guys =)

This is just a shot in the dark, but is it possible to switch between the name server and CNAME entry methods without any further configuration from miraheze? (as listed in https://meta.miraheze.org/wiki/Custom_domains)

The one with www should be the main one I think.

Thank you for the help!
However, there's a bit of a problem. The custom domain only works with "www." in the URL. Could this be changed so it redirects just "portalsofphereon.com" as well?
I can't fix it on my end since I changed the name servers to Miraheze's.

A quick note that the name servers seem to have updated now. Unlike when I made this request, going to the domain now takes you to the miraheze home page.