XDCAM import broken? No Audio!

Help!

Has FCPX/Quicktime dropped XDCAM support? I have been viewing and importing xdcam without issue for years and suddenly today I get no audio, either in QT playback or after importing to FCPX.

I'm running fcpx 11.0.1 and QT 10.5

the files are definitely fine. they play on the Sony Catalyst browser and on VLC player.

What has happened? If there is a codec omission in the new ProFormats, how can I restore the old codec (or even find it?) (maybe in time machine?)

according to System Info, I have Pro Video Formats 2.3.2 installed, which CLAIMS to have have XDCAM on the website.

Help! what could be happening here? Thanks.