Chalice 'bleaching'...only not

So, about 6 months ago I got this awesome chalice, bright red and about 6 inches across, and everything was fine for about four months. It rested about 4 inches off my sandbed in the rockwork. Without moving it and without anything changing, it suddenly developed what looked like white 'blisters' really close to the center of the chalice, just off from the middle. I dipped it before I put it in my tank of course, when those developed it didn't look like bleaching, because it looked like the tissue swelled rather than receeding, so I took it out and dipped it again. More of those spots developed though, and have spread over the chalice. I moved it into the shade thinking that may help (Worked on another chalice I had), but it only made issues worse.

I keep ALOT of chalices, and not a single one of the others in my tank are showing any signs of anything being wrong. My water parameters are great, but I'll admit, thanks to health problems they haven't been the most stable the last two months. I've been in and out of the hospital and Operating Room alot I've tried upping the magnesium levels since Chalices love the Magnesium stuff, but that hasn't helped either.

Any other suggestions? Any idea what this might be?

 

One of the main characteristics of being blister like, is being red (it's a red chalice.) So, the main thing is that there are parts that have swelled? Pictures would be great.

In that case, there is not much more you can do other than keep on checking on your other chalice. You are already dipping it.

But, my best guess would be that it will be fine. LPS will sometimes swell in weird and whimsical ways.

 

AKA I have no idea what it is; but keep an eye out