leather coral dying

My toadstool slumped and retract it's polyps. I've had this leather for 6 month now and then 3 month ago I relocated it here in the 10 gallon. It had doing well since I moved it here, it's getting good amount of flow and light, no problem at all. Then suddenly this happen. It has been like this...

Hey all, I recently ordered some corals from Top Shelf, as well as a leather coral from a LFS & I'm not having very good luck with them. I had some zooanthids in the tank prior that are all doing great, as well as a star polyp that's doing good. Once I acclimated the corals & settled them...