Many elegance do this in the first 6 months of captivity and often times they look much worse before turning around.
it’s common to pls e them in low flow but in nature they get lots of flow snd do better in medium flow in our tanks. I sugguest feeding it once or twice a week with meaty or pellet good. Give it medium flow and most the time after looking bad for a while they return to normal appearance.
this is based off my experience keeping many elegance corals over many years.