I recently switched to WPMU as my host, and I think there maybe some issues with global DNS resolution.
Its been just over 48 hours since I changed all my A records, AAAA records and CNAME. The site works ok for me on my pc, but some of the DNS checker tools (Ive been using a few) still show it unresolved in some areas of the world.
As a sanity check, I just typed in my IP address into my browser,
It pops up an error page that you can likely see if you type that into your own browser. it says something about adding the domain, but I have done that and have made it primary.