When I playing My Career mode. When I'm rebounding the ball when I'm on the mid air and the AI rebounds it too I got pushed in the mid air. Same as Defensive and Offensive rebound.
How high is your Strength rating? Defensive and Offensive Rebounding rating?
All of these factors come into play. Even if you think you have good position to rebound, a CPU player with better rebounding and strength ratings will still get the rebound a lot of timess. It is annoying but you just have to up your ratings with VC or SP