Axis tilt or the lack of it, is what makes the ball track where it does. You can throw any amount of axis rotation and you will track in about the same place. It's not a big deal if you never track any lower. It's a little hard for me to help you change your tilt without me being there but you can try one little trick. Try rolling the ball more with your middle finger and less with your ring finger. Sometimes that will cause some bowlers to tilt the ball a little.
Bowl great!
Ron Clifton