When the screen pops up, the upper limit is determined by the number of revolutions of the motor, not the actual position of the screen. Over time, this limit seems to go out of adjustment.

To "trick" the limit, while the screen is moving up, quickly press down or tap on the screen so it momentarily moves downward then resumes raising as soon as you let go of it. When done correctly, the screen should raise fully; if you hold it too long, the screen will retract.