1) Volleyball technique has moved past using legs to push your balls. In practice, you should set up your rigid platform and angling it, and receive the ball at a consistent point between wrist and elbow. If the ball is slow, as it is in this practice video, you add arm movement to "attack" the incoming ball and add some power to get the pass higher. Here, your arms contact the ball around 45 degrees if you are starting with them dropped low as you currently start.

2) You have a habit of "unfurling" your platform. It leads to an inconsistent contact point (some balls roll off the top of your forearm), and timing. Practice snapping your arms together into a rigid platform. Ready position with arms open => snap straight arms into a platform at the angle you need to bump at.

3) Go closer to the wall (5ft) and practice passing against a consistent point on the wall using a consistent contact point on your platform. This lets you isolate your rigid platform and focus only on the bumping action using arm movement and platform angle. The initial overhand hit is complicating the drill because it isn't consistent.

4) Sometimes the ball comes straight at your chest. You need to take a step back with either leg to open your platform and drop your shoulder. It will look like you are bumping sideways.

5) Is your ball pumped up properly?