I’m encountering a problem with the configuration of a custom domain for my CDN. I have correctly set up my DNS settings (see just below) and I can’t find any solution in the documentation or via Google.
The name is proxied by Cloudflare, so Cloudflare return Cloudflare IP addresses in DNS lookups for this hostname, and not the CNAME value you have configured. This is the expected behaviour for hostnames. Just change your test to use A and AAAA instead of CNAME.