Help!! Something is killing my Montipora!

[C_Reefer]

Hello! I recently purchased a montipora capricornis online and it has undertaken some serious damage. At first I thought it was bleaching but I don’t think that’s the case as the other corals I have, including 2 other montis of different species, are doing just fine. Perhaps something is eating it?
What should I do? There seemed to be no pests on it and the site I got it from is reputable.
Parameters are all stable and in recommended spots.

if something was to eat it my suspicions lie to my sailfin blenny or my tuxedo urchin, but I’ve never heard of either trying to eat coral

 

[C_Reefer]

Hello! I recently purchased a montipora capricornis online and it has undertaken some serious damage. At first I thought it was bleaching but I don’t think that’s the case as the other corals I have, including 2 other montis of different species, are doing just fine. Perhaps something is eating it?
What should I do? There seemed to be no pests on it and the site I got it from is reputable.
Parameters are all stable and in recommended spots.

if something was to eat it my suspicions lie to my sailfin blenny or my tuxedo urchin, but I’ve never heard of either trying to eat coral

When I got the coral 2 days ago it was in perfect condition

 

[amazongb]

What color is it supposed to be? Montis like lower/mid light..

 

[C_Reefer]

What color is it supposed to be? Montis like lower/mid light..

It’s supposed to be red. It feels like it’s been too quick for it to bleach and it spent a day under my lights and was fine.