Hello, I created a subdomain and when I log in to the site, I get an unsafe error. No problem with main domain name "None of the common names in the certificate match the name that was entered (sub.example.com). You may receive an error when accessing this site in a web browser. Learn more about name mismatch errors." How can I fix this? do I need to check LE in the website settings again?
When the LE checkbox of the site gets unchecked, then this means that LE refused to issue a cert. See FAQ to find out why: https://forum.howtoforge.com/threads/lets-encrypt-error-faq.74179/ Yu must enable the checkbox again to try to get a new SSL cert.
Take care of pointing the intended sub domain to the web server as well. It is a common mistake not to point it at the web server and let it properly propagated before asking for LE certs for it.