until the latest versions of Plesk, until a few weeks ago, I access all the web servers using "https://server.domain.com:8443" with the latest updates all the servers are blocked and only work using ipaddess:8443
If you want, with private message, I can send you the addess of all the webservers.
I've the same problem. I currently use a customized hostname for my webserver. If I try to enter using the IP-ADDRESS:8443 I can enter. With HOSTNAME:8443 I receive an error (seems like the firewall lock the access using an hostname.) Please write in this thread if you found a solution to use...