I have a Red Vol, Green Wolf Eel, Panther Grouper, and Clown Trigger.
I started with the Red Vol, and he was stubborn as heck about eating. The LFS only fed him guppies, so he wanted live feeders. I knew this wasn't great for him, so I was determined to feed him frozen krill and silversides. I tried wiggling the stick, being patient, but nothing worked. he just wouldn't eat off the stick. Then I accidentally dropped a small piece of krill on the surface, and sushi (the lion fish) gulped it up! I guess the movement interested him. Once I paired him with the panther grouper (Eldridge), he got straight up competitive about the krill, so feeding was a snap.
My advice is stop using feeders altogether. Give it a couple or three days to let them get good and hungry, then float a few small pieces of krill or silverside on the surface. If they show interest, put a few more pieces in the tank. If not, pack up the food and wiat until the next day. A lion can go for days without eating; he won't starve, but he does get spoiled. Just like the first time you try to wean a baby off the bottle to a sippy cup, he will resist. But you have to keep at it, or you'll be stuck with feeders forever.
Freshwater fish are kind of like fast food; they're fun to eat (at least fun for us to watch), but do not provide the nutrients marine fish need for a healthy life. Also, live feeders can carry parasites.
I hope you are successful. It was very frustrating for me, too!
~John