I'm new and I don't know how to report a possiblr bug since I'm not a premium user. So I'll mention it here.
On the Let’s Encrypt SSL Certificate page, at the bottom, when I click on the buttons to copy the certificate to various services, after the process is complete, the button for that service is no longer there, except the Dovecot button. After I clicked the Dovecot button, it processed and the next page showed it was successful:
Copying certificate and key to Dovecot files .. .. wrote out certificate and CA in /etc/dovecot/private/dovecot.pem, and key in /etc/dovecot/private/dovecot.key Enabling SSL in Dovecot configuration .. .. done But when I return to the SSL Cerificate management page, the button is still there and Dovecot doesn’t appear in the list of services already using the certificate like all of the other services that were processed. The list: “This SSL certificate is already being used by : Webmin, Usermin, Postfix, ProFTPD”