Finger Leather Coral Damage/Issue

I have a Finger Leather Coral I have had for like four or five months. It has been thriving in my tank since I got it. No issue until now and it has even been growing by leaps and bounds.
At the base of each finger (on the inside - where the fingers meet the base of the coral) there appears to be multiple white craters. These craters started appearing about a month ago and the are becoming more prevalent as the days go by. Besides the craters nothing else seems to be wrong. The corals polyps come out like normal. It fully expands frequently and appears quite healthy expect for the craters white are getting larger and more frequent.
I have a Green Clown Goby who has taken up residence in it, but I really cannot see him eating this coral. That seems far fetched to me but What do you all think?
I also have a Starry Blenny who likes to dump sand on top of it, so every so often i have to blow off sand that collects in the base of the Finger Leather. Pretty much right were the craters are appearing, which I thought might be related? Thoughts?
Attached are the pictures of the coral and craters. Some said it could be the coral reproducing via division, but they did not elaborate on that or explain why they think that. Do ya'll think its that simple? ​

 

It looks to me like some sort of irritation?

 

I know some leathers will just break off when they get to big that could be a sign of that. Or it could just be something in your tank irritating it like fish keeper said. Have any clowns? Clowns love leathers, mine personally spends almost as much time in my leathers as his nemo and it sometimes irritates and they won't open for a few days.

 

A Green Clown Goby has taken up residence in it and barely leaves. He is only an inch long and appears to be quite delicate in it. That is unless he is eating it..... Could it be the coral is dividing/reproducing? or dying? Someone stated it could be bleaching but i'm not so sure because of the indentations or craters that accompany the white spots. I have never heard of craterous tissue loss involved in bleaching. The most dramatic part of this issue is the tissue loss in the crater. the white spots are disturbing but it is the indentations that are the most confusing part.

 

Same thing is happening to mine. I'll see if I have some pictures, or I'll take some tonight.

I've had mine for 6 months+ and it's been doing it ever since I have had mine. I had a little piece come off the other day, I had to help it all the way off with a razor blade. The spot is healed back up now, which made it more odd, since the other spots are still there.

 

do the spots correlate with where your goby lies in it?