As my avatar suggests, I have experience w aquarium lighting after a decade of coral propagation. Lights definitely color shift as they get old. Especially T5 lighting like you might have in a 36” hood. Long before they stop glowing, the light could be dramatically different than when it was new. They fade gradually too, so old lights are probably not the problem. But, new lights would be dramatically brighter. That could upset the boy?
In one of your replies, you kinda suggest that you hand feed him? Our beardie is going on 7 yrs now, and he has never taken food from our hands. Eats like a hog from his salad bowl, and won’t stop chasing crickets ‘til the last one’s gone. But he has no interest in something from the hand. Yours might be equally uncomfortable?