Coincidence you posted this. I have an eight month old tank and three months ago, I bought a 6-piece Battlebox. I dipped each piece in CoralX, placed each frag in the sand for a few days, and mounted them high light/high flow. Each of the six pieces is thriving: extending polyps, bright coloring, encrusting over rock structure, etc.
Two months ago I bought a few specific pieces from BC, including a Bird of Paradise bird's nest, which I thought were almost bullet proof. The specimen that I was sent looked super-healthy and I put it through the same acclimation and mounting, but in two weeks all of the tissue was melted away and I was left with a skeleton. I tried to move it around in different light and flow, but to no avail. I cannot explain it, but I just chalked it up to one of the mysteries of our hobby. Not a satisfying answer, but I could not think of another.