if it isnt bullying, my guess it would be starvation ,i am having problems with my clowns eating anything .
they only like raw frozen shrimp ,chopped up small ,and the frozen cubes .
They dont seem to fancy the flakes or the shrimp pellets , god only knows why .
Getting fish from LFS u dont know if they are starving i would go as far as over feeding for 2 days then wait and see .
I over fed my tank 2weeks as i got 2 goby's and LG brittle star and 4 different corals ,all have survived 2 weeks so far and now we are going in to clean up our mess
, i just dont trust any store as they are non refundable and i didnt want to loose the goby's they cost me 60+tax ,corals were 40+tax each .if they starve them enough when we get them they die and no refund we have to buy again ,call me paranoid but only one person will profit and it isnt me ! lol
good luck !