Literally just created account to post this. Apologies if this is not the correct way to propose a contribution.
Took half a day of hair-pulling & wondering why a specific subdomain/CNAME just wouldn’t resolve to my server’s IP. Toggled CF proxy settings, router & firewall settings, browser settings, local DNS caches, etc. etc. And finally found the culprit – that particular subdomain was assigned as Route to an old project Worker that is no longer maintained!
Hope this helps someone save time!