Porcupine Puffer not eating

[Simons]

Tank is 6 months old, all the same fish. Ammonia, Nitrite levels are 0, nitrate is about 5ppm and has been since my tank finished it's initial cycle.

He was always an aggressive eater and knew when it was dinner time.

I feed frozen shrimp, mysis and squid, garlic infused. About 1.5 weeks ago he just stopped eating. There are no visible signs of illness..all other fish are eating well.

Puffy isn't getting picked on though at times my cleaner wrasse does **** him off.

Not sure what to try now or is this just a case of a PP hunger strike that I have heard is common with these fish.

Tank has lots of hiding spots, 200 lbs of rock with lots of holes and other places to disappear into.

I can't even see his teeth when he eats so I assume they are not getting too large.

Just looking for some ideas to stimulate a feeding response.

Tank mates:
2 x yellow tangs
2 x butterfly
1 x Niger trigger
1 x undulated trigger
1 x cleaner wrasse
1 x Picasso trigger

All of the fish are smaller than he is and they all stay out of his way. I am running GFO, carbon normal PH and temp range with no spikes recorded. Lots of flow in the tank...open to ideas? Live shrimp maybe??