After listening/watching your stropping video a few times, I heard and saw a potential issue. The stropping sound seemed heavy to me, that might be the surface of the leather strop or it might be too much pressure. It's impossible to know for sure without being there, the blade on leather sounded too scratchy to my ears. The second thing I saw was the handle (scales) of your razor was at too much an angle to the blade, looked to be about 45 degrees or so. This will put more pressure on the blade to the strop. Try to keep the razor scales in line with the blade during your stropping, blade and handle should form a straight line. It might just be my opinion but you'll have better control over the razor "flip" and easier control over pressure.