Well this was an interesting readthrough…
To answer your initial question—this appears to be a sinularia leather based on your first picture, though the second pic could be a Kenya tree. Kenya trees tend to have shorter, fuzzier branches than sinularia.
In both cases, they tend to have periods of decline as well as periods of growth, and will occasionally shed branches to reproduce. While falling apart to reproduce is far more frequent for a Kenya tree, it is not unheard of for other leather corals. If this is the only coral of yours that has receded like this, I would say that it is likely going through a shedding or reproductive process rather than dying. I recommend that you post the parameters so we can better determine whether there is a bigger issue. The second image looks like it may be a little bleached, which would indicate nutrient deficiencies. Because describing parameters as “perfect” can be subjective, providing actual numbers will help us give better advice.
Apologies if anyone seemed a little abrasive—I think for the most part people were just trying to give you a heads up for how the Emergency tag should be used. I’m sorry to hear that your coral melted back. I’ve been there and it’s not a great feeling.
However, the emergency tag is usually utilized when someone is experiencing mass die-off in their tanks or needs to quickly identify a fast-acting disease. The tag is especially important to us Fish Medics and other experts, as it helps us easily identify an emergency and offer a quick solution. Your initial post was asking to identify whether the coral was a Kenya tree or a sinularia. That is not an emergency, that is a simple question with a simple answer. Had you provided all the information including the fact that it was melting back in your initial post, then it may have been treated more as an emergency. Misusing the Emergency tag can be extremely frustrating for those trying to filter out urgent matters from non-urgent ones, and seeing simple questions labeled with this tag can be distracting. General questions like these are better off being open to general discussion.
Also, be sure to keep that sinularia/tree coral away from other corals. In my experience, sinularia can grow fast and outcompete neighboring corals, especially SPS and non-stinging LPS! I hope this helps.