I have been in and out of forums checking on most queries for this, but in my particular instance, not many have solved this issue that I suspect might have something to do with the FQDN relationship between certificate and host server being .local vs .com.
When I browse externally to URL https://remote.server.com
I can log in (with either a standard user or admin) and I am presented with 'RemoteApps', however, when I log in on the local server (as admin or standard user) I am presented with 'RemoteApps' along with 'Connect to a Remote PC'; which is exactly what I want to see when I log in externally from any client.
So, to add some insight into what I can confirm:
TCP Port 3389 & 443 are open.
I am using Internet Explorer (after reading about the ActiveX trap)
IIS show desktops is set to TRUE
Tested with Firewall OFF, Tested with AntiVirus OFF
My server has a hostname of DC-FS01
My SSL certificate has an FQDN of remote.server.com however, internally my hostname looks like DC-FS01.server.local
I have a Forward Zone called remote.server.com that points to the internal server / DNS server IP address, and can ping remote.server.com internally.
I read somewhere that I should be able to ping remote.server.com and get a response, this does not happen in my instance, but I find that strange if I am meant to be able to achieve this when I am going through a browser.
Any insight or advice into this would be much appreciated.