I really doubt that multiple Trainz installs causes a problem. Plenty of people on this forum have not only multiple versions but multiple copies of the same version!
Interesting that I'm not logged in but I'm not getting Trainz Plus through Auran/N3V, I have it through Steam, so I would assume the authentication is done through Steam.
Trainz Plus is working fine, not gonna fix what's not broken
If I were going to keep Trainz Plus, maybe I would, but I only bought Trainz Plus for the FCT, really, and to check out Trainz Living Railroad.
But the goal remains to get the TRS 2022 PE install working too, that's my permanent install regardless of whether I pay for Trainz Plus in a given month.
Thanks again for all your help! It's very much appreciated.
Now I was able to go back to N3V and prove to them my network and environment are fine.
Maybe by this time tomorrow I'll be posting their next answer.