When I first got my sun coral, it refused to eat being target fed. I found using the top half of a pop bottle to cover it, then insert mysis (after being thawed in sw in a dish) from a pipette then let sit for 5 minutes, then go swirl/create flow inside the bottle, then repeat.. It came back very quickly after 2 weeks of this, every 3-4 days.
Also important, keep tracking of your feeding schedule on a calendar incase you don't already
