I have a small colony of small red (well, orangey-red) zoas that just aren't doing well. They're not closed all the time or anything, just not getting growth like all the others in the tank (I have quite a few zoas). I think some of it is that it kept getting moved by a snail for a while, but so have some of the others. Right now they're next to some other ones that were bought at the same time and those are really booming LOL. Unfortunately, not a lot of good spots to place them.
I also have some purple palys that grew well in more light, but were losing their purple. I moved them to the shade so they're purple, but not growing LOL.
Neither of those is any big heartache, though, just a tad frustrating sometimes when I look at pics of everything over time. I think I've been very fortunate to not have had any of the issues that seem so common with zoas & palys. I look forward to getting our 140 up and running, then I'll have more room to give stuff better spots in a tank!