+1 to all the responses.
I don't have much to add but went through a similar experience recently. My buddy wouldn't eat the NLS, even if I soaked or made them smaller. He likes the Hikari Bio-Gold, soaked in garlic juice (I use Garlic Guard). I'm getting some Omega One to try because I heard the Hikari isn't the highest quality anymore.
At one point, my fish only wanted bloodworms.
I held off feeding him about a day and half and then he got excited about pellets again. Sometimes, you have to try tough love!