I only ask you one question, where is the left hand on the ball when shooting? The standard position should be the upper left of your right hand.

When shooting, the palm of your left hand should be inclined to you, and the basket is right in front of you! ? Look at this picture.

If the left hand holds the ball in the correct position, the right hand will exert its force "straight up" and the left hand can only exert its force "obliquely behind". The left hand will not interfere with the right hand!

So I think you may have two questions.

1? The left hand holds the ball in the wrong position.

2? In the process of completing the shooting action, the action is out of shape? Thereby changing the direction of the left palm.

Finally, the left hand interferes with the shooting.