This is feedback only, I don’t need help
In the Fly dashboard, in the section Certificates, the Confirm domain ownership box shows a little red dot. I interpret this red dot as “Something is wrong” and I checked whether the CNAME record for hostname verification is in place in DNS, and it is, so all is fine.
The red dot should be a green dot.
Imho, this is just a little bug you should fix to prevent customers from getting scared about something perhaps being wrong with their cert and spending time on figuring this out, contacting support, etc.