I have a Normal male, who's about 16 months old, who no longer strikes at / constricts his f/t feeder rats and mice (he'll happily take either, thank goodness). At first I thought he was on a "hunger strike," but now I'm really not sure. In his first year, he was an aggressive eater, and couldn't wait to snatch feeders off the tongs, so when he stopped striking, I was a little bewildered. But he comes right out of his hide when I scent the room with a blowdryer. And while he doesn't strike, anything and everything that's left in the cage disappears.
I'm sharing this because it might also apply to other "problem feeders" who are on f/t. I'm suggesting you leave "refused" f/t food in the cage for awhile to see if it works if you. The behavior sort of makes sense, because striking and constricting in this case would consume unnecessary energy.
Comments welcome.