I found the issue. It seems that the password to my login on the remote machine is the problem. The remote machine is equipped with facial recognition and I had set it up with that without ever having to type my password in. So, I never encountered the issue until I tried a remote login using NoMachine. I immediately created a new admin account on the remote computer and was able to use NoMachine with no problem thereafter.
So, NoMachine effectively found a potential issue which may have turned into a disaster if the facial recognition ever failed on my computer.
I’m using it now and am very happy with its performance. I just wish that the display management to the remote machine was a bit more intuitive. Sometimes I forget where to find the display controls (it’s not under settings). A quick method of switching between monitors on the remote machine and an easy way to change the resolution would be great. The other issue is the viewport mode. It seems to zoom in too much and there doesn’t seem to be a way to zoom out to a more comfortable screen view.