Vegas Pro 13. 1.5 hour project from 2 ProRes 422 .mov files. Presently the project is about 1/2 complete with 13 markers and 10 splits along the timeline. Original media only carried left and right audio, and timeline's audio tracks were correspondingly  reduced to 2, (left and right stereo) prior to editing. Originally the audio was fine until after 4 hours of editing, when all but the first 8 minute split of the right audio track disappeared so that the balance of the 1.5 hour right audio  track is blank.  The original .mov files are still in tact. How can I recover the missing split segments of the audio without redoing all edits, splits and markers?