SSL cert won't issue

I’ve successfully set up SSL before and today am trying to set up the default Let’s Encrypt SSL using https://fly.io/blog/how-to-custom-domains-with-fly/, but it’s been over 15 minutes and the certs still aren’t issued…

Any response to this? I’ve completely recreated one of the apps, with a brand new IP address, and still no joy.

If you are using Cloudflare, disable the Universal SSL on Cloudflare.