I swung by a dealership today to see if they would load up the update. I was told that the update would not work because it was for the 3C 8.4 and I have the 4C 8.4, also no such thing as a secret or double secret update lol.
Well, I don't now what radio is in my 2018 Hellcat but what I was told was the tech said Chrysler was called by him after the tech confirmed the NAV system was truly acting up. I had already confirmed at the uConnect web site my radio's software was up to date.
After he downloaded and applied this first unpublished update, maybe I should not have referred to is as secret update (though in some way it was secret in that uConnect did not list it), and the NAV unit was still acting up he called Chrysler again and was told there was yet another unpublished update. Most likely both of these updates were in beta testing. (In my career as a software engineer I released my share of beta versions to selected customer sites to try to confirm the issues the customer was seeing were resolved by my fixes.) At any rate the 2nd update was obtained and applied. Still the NAV was not right.
At this point then the bezel was removed to get at the radio and its numbers so the right radio could be ordered. It came in and was installed. I do not know which radio my car has -- it might be listed on the work invoice -- or which software update it was given at the dealer after it was installed in the car but I do know the menu and icon colors are different from what they were before any of these updates were applied so it apparently doesn't have the last published radio update which I guess is the one still available at the uConnect site.