Here's a repair that worked excellently for me. My video runs slightly faster than the audio over the length of a shot.  You may need to do the adjustment opposite to me. Right click the audio track and generate the sound graphic. The progress bar is at the top, and takes a while to complete. In edit: Ungroup the video and audio.  The beginning of the shot is in sync, so go to the end of the shot, Right click the audio track. Dialogue box opens. Click Timestretch/something. Control panel opens. Click "power". The control is very sensitive, so it is necessary to use the numbers instead of the knob or screen-type graphic. And you have to do a bit of lip reading. The vowels are loudest, so pick an "o" or whatever, and mark it with the cursor. Observe the "o" sound on the audio track. If the audio track is too long, make the number in the Tempo box very slightly larger. Example: change 120.1 to 120.14. Experiment. What happens is that the beginning stays as is, but the track is stretched or shortened, which corrects the sync drift. When finished, select both video and audio track together by dragging the cursor over them, and hold them selected while pressing ctrl-l (I think). Check that by holding your mouse arrow over the "group" icon. This is a lot of time, and doesn't prevent the drift problem, but if you're desperate, it works very well. Make sure to save the project.