Waveform for only part of the file

I have some video interviews which have fully working audio in V14....problem is only half of one of the 40min interviews has a waveform. The file has a waveform in the media page and on the timeline....but only for the first 20 or so minutes of it. The rest did not generate and displays as a blank audio waveform.

Just to be clear this is on 1 continuous file...and only 1/2 the waveform is showing.

I set my working directory to a new cache and restarted davinci...but that didnt seem to fix it....

Where are the waveform cache files located? and is there a way to force davinci to regenerate them?

Thanks

so on further review.....i think I see the problem...or bug

This is a mxf file consisting of 4x 2gb chunks....formatted for fat32 CF storage as is common...4 files representing 1 continuous video.
The waveform cuts off at exactly the end of the second 2gb chunk. The audio and the video are still fine...but no waveform is generated for chunks 3 and 4.

Still have no control over this, other than possibly removing the individual clips from the folder to force davinci to treat it as 4 individual clips, but that's a terrible workflow

[Peter Chamberlain]

Can you PM a link to the source file?
What is is recorded on?

sorry cant for security reasons
North Korean defectors...have to hide identity, family still present.

The XML says shot on canon xf100 firmware 1.0.2.0