Pocket Pets feeds Glider Gravy(which is the same as HPW Complete) along side pellets. I would mix up the Glider Gravy and offer that along with the HPW you made(i"m assuming its the original recipe? with bee pollen, eggs, etc?) Gradually decrease the amount of the old diet and increase the new.
Also, make sure to offer him a variety of fruits and veggies to eat as well.
Moving to a new home and being separated from his parents is VERY stressful - often they don't want to eat for a bit so offer him the Glider Gravy which should be familiar and slowly transition him over.