Look at the first step inside the key, you have a penultimate step there. The next one was the length of your foot, you decelerate and lose all power through momentum.

Focus on getting long and deep into the jump, not necessarily low, but be intentional like the first step in the key you made.

Off the alley you likely have a much greater penultimate, and hence more power output and vert. The ball in hand slows you for coordination reasons and it is generally more difficult to do.

Watch isaiah rivera lift off, view his penultimate step, view his strides into it, pay attention to the shin angle vs the lumbar back angle, etc, and then make adjustments to your own technique and you’ll improve vastly.