Thanks for sharing. The file has issues. 10 channels of audio are listed, which is likely why there's no audio.
However, testing CROP and various speeds up to 400%, the problem that you cited could not be replicated here.
When using high speeds only a single thumbnail may display, but all content is there. Move the slider (bottom-right of the window) and more thumbnails may be revealed... 
See your PM for a link to the reencoded file.