Ahh, i think the problem here is we still own the myDMX 2.0 version hardware. Am I correct in assuming myDMX3 does not work with myDMX 2.0 Hardware?
As a user, I did a google search for the latest version of the software that last works with the DMX 2.0 hardware, and find this page: https://www.adj.com/mydmx-2-1 (same is true for https://www.adj.com/mydmx-2-0) that contains the version (September 29th 2020) that appears to be the last version put out, but gives the user experience we have detailed.
The myDMX 3 package you reference above installs, and looks great, but It does not seem to detect my myDMX 2.0 hardware. Let me know the right way to proceed here.