Advance Pulldown option not working in FCP 10.4.4. Anyone?

I just updated to the latest version of FCP 10.4.4 and noticed that when I tried to import some 1080/24pa footage from a P2 card that I use in my HVX200 the remove advance pulldown option is greyed out not allowing me to click on it. And so when the footage is imported none of the flagged frames are removed. I have tried removing the A52codec but I can't find it anywhere on my Mac mini, nor do I have Perian or any of its components installed. I have performed a very thorough search of my system for any pieces of this software numerous times. The option does work if I re-install an old version of FCP, which I am lucky enough to have on an older machine. FCP 10.3.4 works fine but does not allow the addition of subs which is kind of nice to have.

So does anyone have any thoughts or ideas? I have contacted Apple support which frankly was a waste of time. I also tried the resetting of preferences in FCP. Did not work.

Cheers.