Issue with Remote desktop Services within Direct Access

I have set up Remote Desktop Services on a Windows 2012 R2 Server.  Internally everything is working as expected.  The next stage is to get it to work via DirectAccess. 

I can log into DirectAccess as me (member of the Domain Admin group) and get to the RDWeb page,  but when I click on the RemoteApp Program,  I get the "Remote Desktop can't connect to the remote computer for one of these Reasons:  etc."

But if still logged into DirectAccess as me, I log into the RemoteApp program as the Domain Administrator it all works as it should.

Anybody have any ideas?