I have removed the server and tried to re-add it with it's Public name. I have also checked the SSL Box (using port 8531), but getting the error:
Cannot Connect to 'UPDATE.DOMAIN.COM'. Please make sure the Post-Installation task is completed successfully in that server. If it was, please verify if the server is using another port og different Secure Sockets Layer (SSL) setting.
If you can connect w/o SSL using port 8530, then think you need to add ssl binding in IIS on port 8531
c:\windows\system32\inetsrv\appcmd set site "Default Web Site" /+bindings.[protocol='https',bindingInformation='*:8531:']