How are you feeding him? If it is a bowl method he may not understand. You may need to get a feeder run and put it in the cage. I would advice against free feeding. If he has a parasite load they continue to reinfect themselves through fecal. So the insects crawl through it and then they eat the insect with the eggs of the parasite on it. The cycle just continues. This makes it much harder as well if your medicating for a parasite after a positive fecal test.
Next what are you feeding him. Try to go with something like crickets that he would know is food.
Next what are you feeding him. Try to go with something like crickets that he would know is food.