Question for the group regarding the Administration Hub, for those that have experience with it.

I recently completed an upgrade to LF12 in an environment that has 9 servers. I've installed the Admin Hub Agent on all of those machines, and most of them are connecting and showing properly in the Hub on the main app server. However, I noticed that the admin hub is duplicating the servers. Each one has an entry for a server with the FQDN, and another for just the host name. The entries with the host name only are not connecting. This isn't a major issue, as we can simply select the "Running" tab, but I wonder if anyone knows why this is happening?

Also, and the more important issue, the admin hub is not connecting to 2 of the servers that have the agent running on them. It can clearly see the apps on the server, but it is not fully connecting. There is nothing different about these 2 VMS, they are on the same network, same OS, same domain. I've tried restarting the agent service on these 2 VMs, as well as the administration hub service and agent on the main app server, which doesn't help. Are there specific ports that need to be opened between the agent machines and the admin hub machine? I have a screenshot included for reference. Any help would be appreciated.