Could be a number of things, but because these aren't stony corals, they aren't AS dependant on supplements (though they still need and use them). If you've run out and haven't added any in over a week or so, then you can naturally assume that the chemistry in your tank has significantly changed, which could be the reason for their upset. Additionally, changes in lighting, current and position in the tank can also affect how "happy" they look/are. Futhermore, tanmates can be bothersome to softies as well. Keep an eye on any inverts you have, look for bristle worms in the rocks where they are attached, and remember to check your water params. If they aren't flipping themselves inside-out and tossin their guts to the wind, and if they aren't draining in color, or falling apart, then more than likely, they will be fine, and are just either being irritated, or lacking proper nutition.