"Unfortunately this stops DNS traffic before it gets to Cloudflare so it is not a problem we can solve for you as much as we would love to. Our recommendation right now would be to contact your domain registrar to understand more about this problem."
Contacted the registrar (iwantmyname.com) and their response:
"You're using external CloudFlare hosting, so our DNS management isn't being used. We don't have any access to the hosting account or the ability to address issues there. It does appear there's some issue with propagation."