You're probably stressing for nothing
. Stuff opens and closes all the time, sometimes closes for days. It's all part of salt water tanks. If you can figure what triggers them to open and close then you might get ahead of it a bit but really... I wouldn't expect to figure things out, ever! I have critters that do great in one tank and terrible in another with no apparent reason why. It's all part of the game and the sooner you can treat it with wonder rather than frustration the more you can enjoy the crazy randomness that Reefs are
.
Dan