Enter-PSSession UriFormatException

I am attempting to install Remote Desktop Services in Windows Server 2012 and am getting a fail on "Specify RD Connection Broker Server". The compatibility check failed with "Unable to connect to the server by using Windows PowerShell remoting. (I don't normally use power shell.)

The Server name is "Test.<domainname>._internal".

When I try to connect with power shell and a manual PSRemoting command, using "Test", it connects. When I try the full name, it fails with:

enter-pssession : Invalid URI: The hostname could not be parsed.
At line:1 char:1
+ enter-pssession test.<domainname>._internal
+ ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
    + CategoryInfo          : NotSpecified: (:) [Enter-PSSession], UriFormatException
    + FullyQualifiedErrorId : System.UriFormatException,Microsoft.PowerShell.Commands.EnterPSSessionCommand
I get the same results from both the server itself and from the domain controller to the test machine.

Can't PowerShell use standard DNS resolution and handle FQDN's? Or can't it handle the underscore ("_").

Any ideas?

Thanks,
Bob.

PS: <domainname> is the place holder for the actual domain name.