I need a video from the ball side, from head to toe, from start to finish to see everything I need to see, but from what I can see, it looks as though you are bending from the waist and not getting your butt down into the slide. This bad back angle points the ball down into the lane and doesn't allow the ball to land smoothly onto the lane. Think of it like this, the ball follows the angle of your chest, if your chest is pointing down at the point of release, then the ball will head down into the lane, if your chest is pointed toward the pins, the ball will land smoothly onto the lane.
Why is it bad to have your chest pointed down? Because the ball will bounce upon hitting the lane and sit up on top of the oil and hydroplane and not grab the lane properly, where if it hits smooth, it will sit down into the oil and make better contact with the lane and give you a better read of the ball's reaction.
How to do it? 1. Let the ball fall from the top of the back swing, as the ball falls, sit down into the slide, this will get your butt down and keep your chest up and pointed toward the pins.