That's exactly what my Clown trigger does to new frags, picks em up then drops them. Have no idea why and how the heck he knows it's new mixed in the jungle of corals. I actually enjoy it when he does it since he doesn't damage them then after a day he stops.My friend has a picaso in her 300-400g reef too. She says he turns things over and moves thinga but leaves the coral.
We will see over time. I keep him pretty fat and happy. Lol. He just pickin on all the new coral frags i added. New tank taste. Lol
I thought maybe he was cleaning em or eating the small worms and crustanceans off of em. Like the little pods or micro critters. Triggers only have 2 teeth? The two sharp ones? Idk how he knew the new ones vs the old ones either! Lol