Hi Scott!!
This one might be a bit trickier for Fritz, due to his age and the fact that he hasn't fully developed in terms of muscle, bone, etc..
It seems as though when he gets up to the pretty, he is more balancing on his haunches than his butt and haunches combined.
Try, if possible, to keep the lure almost in contact with his muzzle when raising it behind his head, to keep him from jumping. Its ok if he licks the food or tries to get it at this time. By doing this, it might help him achieve the initial position easier. He can also use the base of your palm, while your food is tucked away higher, for balance. If the opportunity presents itself..
Nice job with rewarding the sit, BTW!
Mark
