I have had this wall hammer for a good 4 months now and it has been one of my favorites in this tank and has always opened up fully and looked healthy. In the past two days it has not opened up fully and today morning before the lights went on I see this receding in the center of it and it looks like the skeleton is starting to show. I do not know what can be going wrong. All parameters are in check and stable and all my other corals is looking healthy including other hammers. No change in lighting or flow since it was first introduced. It is also releasing or causing this grey jelly like substance that is white or the same color of the green polyps. Could this be brown jelly disease even though it is not brown? Any ideas help with be greatly appreciated.