I spent sporadically over 2 weeks troubleshooting the issue. The first, was making sure that my ESN had port 8443 opened which took a little time. After that I figured the connection would work and all would be right in the world. Well, after the port was opened, I could not connect. I worked with Jamf Support, spot checking my connection Internally but nothing was making sense as to why I couldn't connect Externally.
My Network Team was watching traffic from the outside to the NetScaler and the could see the attempts, but on the backend, the Server was not "LISTENING" or anything on the External NIC. Being that our servers have Windows Defender it dawned on me to check the settings. Sure enough, the "PUBLIC" or External NIC was NOT authorized.
As a test, I disabled the PUBLIC FW and sure enough, the DMZ side started working. Obviously I'll be getting that STIG adjusted but wanted to share in case others are banging their head against the wall over a similar situation.