Are there any montipora specific pathogens or parasites other than nudis?

[speckled trout]

I made a post about a month ago about my declining montiporas, digis, plating and whorling varieties.

None of my other corals are declining and this has been ongoing for 4 months now.

I have the following :
1. several acros
2. pocilliporas
3. 2 varieties of Birdnest
4. various zoo colonies
5. a couple of frogspawn colonies
6. candy cane
7. numberous varieties of mushrooms/ricordias
8. xenia
9. a couple of varieties of star polyps
10. purple plating monti - showed a slight tip bleaching but seems to have stopped getting worse a couple of weeks ago
11. orange plating monti - has slowly been losing tissue for over a month
12. various species of green plating monti - these have shown various degrees of bleaching, from completely(death) to a little or none
13. orange whorling monti - completely dead after the first month of problems
14. various green/orange/purple digis - the purple was the first to bleach and die. It took only a couple of weeks for this to occur. The orange digis bleached after a month or so, and the green tried to hold on. One of them still has about a cm of bleached polyps on one tip. This tiny section of living tissue has been holding on for around 4 months now.
15. A pink digi - it started bleaching almost immediately upon introduction into the tank. It was a large colony and only 2 tiny tips remain alive and still pink in coloration. They've been holding on for nearly 4 months.

I had a nudibranch infestation about a year ago. I haven't noticed a single one after a lengthy battle and the introduction of a 6 line wrasse. I have inspected them at length and even at night and have never seen another one.

My question is this, what pathogen/parasite is so host specific that it only attacks montiporas? Surely, someone has had this happen to them before.

[speckled trout]

Let me add, the polyps bleach before actually dying. Some of them hold on for a month or more before the tissue actually receeds. I've got several specimens that have bleached areas that are still alive after several months.

[acrylic_300]

Check at night to see if they are sending out tendrils in any area. I had one doing this then noticed a small speck. The next day a picked it with a knife and a chunk fell off and some kind snail looking thing had embedded into the tissue.

This was on a new frag. If it was something like that on a large scale I am not sure what I would do.