The Certificates (CRT) section of cPanel's SSL/TLS tools stores certificate data that can be used for SSL sites.
You can upload or paste a certificate, inspect stored certificates, and remove certificates that are no longer required. Deleting a stored certificate should be done carefully: first confirm which live SSL site or future installation depends on it.
Removing a certificate record does not solve DNS validation, private-key, or hostname problems. Identify the actual cause before deleting certificate material.