I have had them do that before and I would not really worry. If they fail to stand up, I would remove them though. They are super resilient though. I have a Kenya tree that just appeared in the last couple of months. I have not had any in 2+ years and not added anything new in almost as long. It does seem they like their water a little dirty. Dont worry, if your Kenya dies you can have mine, Its stinging another coral.