I tried "Rebuild Previews" but that simply reports the preview up to data. I am trying to find a way to invalidate or delete the previews for the affected videos so that they can be rebuild. Jeffery Friedl has this as an option in his Bag-O-Goodies plugin but for some reason it is disabled for video files. I have reached out to him on that.
Does anyone have an idea for how to do this short of deleting and reimporting the affected videos into the library?