AVCHD error importing in FCPX after Mojave upgrade. MP4's OK

I am not able to import any new (or old) AVCHD footage on any of my 3 camcorders/sd cards and the only thing I can think of it happened after my OSX upgrade from Sierra to Mojave (I hadn't shot since that upgrade)

I have tested this on at least two of the SD cards and even after fully initializing the cards, same error. When I change the recording format to .mp4. the card allows an import.

FCPX can see the AVCHD files however I notice that there is no audio to hear that you can usually scrub, prior to the actual import. I can scrub through MP4 files, however.

Has Mojave changed the way the audio files are read? Or is this a permissions issue now that Mojave always asks about access with new devices (I don't get any prompts, though)

Thank you for the solution.