The domain cf-no-ssl.fleetssl.com is being served through Cloudflare CDN. Any Let's Encrypt certificate installed on the origin server will only encrypt traffic between the server and Cloudflare. It is strongly recommended that the SSL option 'Full SSL (strict)' be enabled.
https://support.cloudflare.com/hc/en-us/articles/200170416-What-do-the-SSL-options-mean-
The domain cf-no-ssl.fleetssl.com is being served through Cloudflare CDN and a certificate has not yet been provisioned yet by Cloudflare.
https://support.cloudflare.com/hc/en-us/articles/203045244-How-long-does-it-take-for-Cloudflare-s-SSL-to-activate-