Let'sencrypt server can't connect to other network

Let’sencrypt servr in Cloudflare’s network can’t connect to opened port in my network 2a00:1763::/32. From other internet I can connect to this port. What could be the problem?

Assuming you mean you are trying to get Letsencrpyt to complete an HTTP-01 challenge to a domain proxied through Cloudflare, you will need to ensure that you allow HTTP from client through Cloudflare to your origin (so “Always use HTTPS” being enabled and maybe other HTTPS redirects in rules will break this).

There’s many threads on here about that so a search should help you. Personally I use DNS-01 with certbot and the Cloudflare API plugin so I don’t need to support HTTP to the origin at all.

You mentioned “opened port”. Note that Cloudflare only supports these ports at the edge…

You can translate those ports to other ports on your origin using origin rules…

Perhaps I wasn’t clear enough. I’ll explain in more detail. I have running web server in my network, and port 443 is open. Cloudflare’s hosting has an online port scanner that says port 443 is closed. And the Llecencrypt’s server cannot connect to this port either.
Other port scanners on the Internet see that port 443 is open on my server. What’s wrong with Cloudflare?

P.S. I used this port scanner on Cloudflare’s hosting before and everything was fine, it correctly detects the status of the ports.