Caulastrea were one of those corals I just couldn't seem to keep. I did get a head, brown with green centers that stayed alive, but wouldn't grow. Tank setup for three years. One day I noticed a small bud on the green centered one so I realized it was finally growing, maybe. I bought a 2-polyp frag of a light blue one from Tampa, and within 6 months it was 8 polyps! I guess that something changed that finally made conditions right for the candy canes in my tank. Don't know what it is. Just don't give up. Eventually you might be able to get them to grow.
Placement might be the key, though. I've always had good luck with ope brains (Lobo's, Trach's, Wells) but recently was surprised when I moved my red Trach only about 6" over on the sand bottom of the tank and the next day it expanded larger than I'd seen it in a long time! So much so that it got it's mantle up onto a nearby Acan. The next morning, it had moved itself far enough away (3") that it was no longer touching the Acan when it expanded!