not sure on your exact cause but i know for me branching hammers are 50/50 i find they cant be touched or it could die off or could take days to come back i have some that are doing awesome with huge growth while i have lost some off the same coral i had half a dozen heads and 4 are healthy and have doubled in size while the other two perished. i find they like the sand i tried in the rocks they werent doing good i put them in the sand and they are growing great could be just me though
