Sorry, I guess that post was still under moderation when I posted.
No, those topics are not related to my issue. Both of those people have issues trying to connect, but ARE getting the external IP to show up during the welcome screen. When I open NoMachine the only number that shows up in the welcome screen is the internal IP. I have also tried getting the external IP elsewhere and then setting it up manually but that doesn’t seem to work either.
From my research the solution to the external IP not showing up has been “Make sure uPNP is enabled”. My problem is that it is enabled and that was the only suggestion I could find.