Is it hard to the touch? Did you put it on the sand bed? What kind of lights.
Doesn't look healthy IMO, I have a brain garden on my sand bed and I had one that looked like that and it got worse. I eventually took it out and brought it back to my buddy, it never came back.
I'd keep a close on it. It almost looks like the skeleton is starting to show.
EDIT:
What about flow? Have you checked your parameters? Also I got this off of the app pocket reef which is a awesome app btw...
They can be aggressive if placed too close to other corals and can emit chemical toxins that will irritate other corals in the tank. These do best if placed in the substrate or floor and will expand and contract during lighting periods to increase surface area and take full advantage of the light. This LPS needs high levels of calcium in the tank to grow.