I have a 2012 RDP gateway that I am having trouble getting some Windows 7 machines to connect to. I've narrowed it down to if the DNS entry uses the CNAME or an A record. Using the A record all Windows 7 machines connect, using the CName some Windows 7 machines connect. The RDP gateway certificate does not have SANs, an oversight on mine when the cert was created.
If it was consistent between machines I would chalk this up to the lack of SANs on the certificate, but the fact that some machines work and others don't, I really want to understand why.