I'm unable to secure my ISPConfig Admin site (8080), using ispconfig_update.sh --force -> Create new ISPConfig SSL certifiace: yes Using ISPConfig 3.2.5 LE log: Type: connection Detail: Fetching http://ispconfigpublicdomain.tld/.well-known/acme-challenge/XXXXX: Connection refused To fix these errors, please make sure that your domain name was entered correctly and the DNS A/AAAA record(s) for that domain contain(s) the right IP address. Additionally, please check that your computer has a publicly routable IP address and that no firewalls are preventing the server from communicating with the client. If you're using the webroot plugin, you should also verify that you are serving files from the webroot path you provided. There are public DNS A records, to the ispconfigpublicdomain.tld site, and websites running on it, works with both HTTP and HTTPS. LE works all over, just not on the admin 8080 site. Any suggestions?
The errror means that Let's encrypt was not able to reach your server from the internet. Check DNS records (ipv4 and ipv6), firewall for port 80 and read let's encrypt FAQ: https://www.howtoforge.com/community/threads/lets-encrypt-error-faq.74179/
There's no IPV6 to this server, therefor no AAAA record. LE works on all other sites, running on the server? Both port 80 + 443 are open.
Ok, but letsencrypt clearly states that this exact subdomain is unreachable from the internet on port 80, so you should investigate why it can't be accessed to solve the issue.