I have stars, yellow and daisey polyps and all mine had opened in the first day. But, I agree with the other posts. I was lucky I guess.
This happened to me, so you may want to check out your tankmates---I had got an evil imposter loawnmower blenny and I couldn't figure out why mine started closing (star), immediately I knew something was wrong, so started testing water and as I was doing this, the evil imposter started taking out my yellow ployps right in front of me (left me 1, isn't that nice)---I knew right then he was the cause, took it out and returned to LFS. Well, from that point it took my stars over a week to fully open up again. I had some open, but the majority were closed. Maybe your damsels or something else is causing it, just a thought.