Thanks for the reply, Chris. The version of Premiere I was on was very recent, if not completely current. My guess is that I had these plugins installed on my old computer, deep in the folder structure somewhere and that allowed me to use them. I guess the migration to the new system cleaned house, along with the plugins. Moving forward, I will definitely be grading everything in Lumetri when using Premiere, but my issue is the current project, which I’m deep into at this point and don’t have the several days time that would ben needed to re-colour grade everything.
Anyway, hopefully a workaround will present itself.