From what I've heard about goniopora, it never stays alive, though I'm sure there is someone on this board who's had success. But I'm sure they could use more details to help you,
How long have you had it?
Have you done a water test?
what are your levels (I.E. Nitrate, Nitrite, Ammonia, Ph, etc.), even if there all 0, what did you test for and what was the level?
Whats your tank setup? How many gallons, skimmer, lighting?
And any other tidbits of information that might help