Please fill out the fields below so we can help you better. Note: you must provide your domain name to get help. Domain names for issued certificates are all made public in Certificate Transparency logs (e.g. https://crt.sh/?q=example.com ), so withholding your domain name here does not increase secrecy, but only makes it harder for us to provide help. My domain is: jellyfin.rimusa.me I ran this command: sudo certbot --nginx -d jellyfin.rimusa.me It produced this output: Certbot failed to authenticate some domains (authenticator: nginx). The Certificate Authority reported these problems: Domain: jellyfin.rimusa.me Type: connection Detail: 46.239.112.183: Fetching http://jellyfin.rimusa.me/.well-known/acme-challenge/omSFNCQNcAe4tkpdAbPsjfMIJpaGNZwnZjkQYuOTK_w: Timeout during connect (likely firewall problem) My web server is (include version): jellyfin 10.11.6 The operating system my web server runs on is (include version): Ubuntu Server 25.10 My hosting provider, if applicable, is: selfhosted I can login to a root shell on my machine (yes or no, or I don't know): yes I'm using a control panel to manage my site (no, or provide the name and version of the control panel): no The version of my client is (e.g. output of certbot --version or certbot-auto --version if you're using Certbot): certbot 4.0.0