Blue Xenia missing

[pulik]

This morning when I checked my tank, I found 1/2 my Blue Xenia missing. It's only a little frag, with a few sprouts on it; now there's even less.... I had it in one location, but then moved it; seemed to like the new location better. Should I try moving the frag again before it's ALL gone? Any ideas what could have made it vanish into thin air?