Unable to view Canon C200 XF-AVC slow-mo footage in FCPX 10.4.3

I just finished filming and MacOS / FCPX 10.4.3 sees the Canon C200 XF-AVC (MXF) Slo-Mo files as audio only files, no video. Actually there is no audio recorded when shooting 120FPS-1920x1080 so the there is no sound.

FCPX does see XF-AVC files shot at 60FPS or slower, just not at higher FPS. The finder displays the correct amount of data. Canon's MXF utility can see and play the files BUT you cannot export out of it so the file type cannot be converted. Compressor and Sorenson Squeeze only see the audio part of the MXF file. I have previously shot slo-mo in MP4 with great success, and unwittingly did not change formats before shooting the XF-AVC footage.

Salvaging the footage would be outstanding! Any help is great appreciated.

After reviewing the web, it appears this issue has been around since April. Is this forum the best way to let Apple know there is an issue?

Thanks,

Stasi