Zenia dying?

[Slyguy00]

So Iv had my xenias for about 2 months. They came attatched to a bubble coral and have been doing great since I added them. It even started to multiply. My water conditions are prety good and everything else appears to be healthy. About a week ago, one of my bubble coral branches started to die and since 2 of the bubbles are gone. Now all 0f a sudden the xenia that is attatched to my bubble coral is starting to die. Has anybody ever seen this or know whats happening? Any help would be appreciated.