We have one, it looked good for a couple of days when we first got it, then sulked for weeks - shrivelled up and shrunk to about a third of its size, or flopped over like it was gong to fall off its rock, or got bigger, but looked pimply with no extended polyps, or inverted itself so that its edges pointed upwards and looked thin and skinny, changed colour and looked as if someone had sprinkled sulphur on it...
It has come right now, but occasionaly has a shrivelled up period for a day or so, sheds it outer layer - as they do to get rid crud off their suface, then comes right again.
I'd leave it and see how it goes, shifting it around all the time may only make matters worse.