I have a problem with a purple haze monti and a superman. They are not extending their polyps, but it's only in the center. See the purple haze....color is off and polyps are not extended in the middle of the piece but the outer .5" rim looks normal. See the pic of the superman, it's polyps are very retracted...but the rainbow montipora on the same piece of branch rock looks just fine. What gives?

PH 8.1-8.35
Alk 10
Ca 450
Mg 1330
Salinity 51.8mS (1.025 SG)
Temp 78-79 any time of day
No recent changes in lighting
No new additions
Etc...

So anyone had this before? I don't see any nudibranch anywhere...