We have a Hyland Hitch & Yes ours will also get stuck very often, but it doesn't phase us any more.
If yours gets stuck, pull the handbrake on tight & chock the wheels, get a 2nd person to jump in the car & put it in drive & carefully take the brake off or put it in gear & slowly let the clutch out, while you have your hand on the hitch release & it pops up nearly every time. Occasionally you may have to do it once or twice in either direction.
Failing that if it hasnt come free after the 3rd attempt stop & you will notice by this time the hitch pin has come free & will spin freely, pull the pin out of the hitch, put your jockey wheel down so it just starts taking the weight & simply drive away, then you will find the hitch will come free from the ball very easy, works every time.
Also when hitching back up, dont stress if the locking clip wont lock in straight away you will find that it locks in every time as soon as you start to move.