Such a peculiar problem - in my StylePicker menu I filter entries to 'latest styles only'!

Looking at the menu vertically:

At the top end I have maybe 40 or 50 of the latest styles (don't understand why they are labelled 2019 though??) - these I can audition fine, and I can 'load song demo' into BB which plays fine!

Below those I have XtraPAK 8 styles, all auditioning fine and I can 'load song demo' which plays fine!

Below that I have a larger section of latest styles - these I can't audition in the normal way with double-clicks, but they 'load song demo' fine.

All of the above 'latest styles' entries are mixed with Bonus Styles, all of which I can audition fine and they 'load song demo' fine.

If you remember - I have BB 2020 Mac installed (program only about 26 Gb) on my internal iMac SSD.
I copied the full 164 Gb content of your SSD (which I received in the post) over to my external My Passport For MAC (plenty of room), and I have pointed BB 2020 RealTracks Preferences to my RealTracks folder on the external My Passport drive!

Hope you can help Andrew, thank you - Carl