Might be still adjusting to your tank. Fish are more comfortable feeding when there are already fish in the tank. For example, I had 3 chromis and only one was brave enough to eat and the other 2 mysteriously disappeared
. Then that single chromis became shyer and more skittish, but when I added the clownfish they ate together and now both are always in the open waiting for food. My chromis loves flakes, doesn't enjoy pellets as much and my clownfish won't eat the flakes, but loves the pellets.
Soaking the flakes in garlic extract will hopefully entice your fish to eat. Might want to try feeding some frozen food too like brine shrimp, mysis, and/or a mix of things.