I've had this elegance for about 4-5 months and it has been one of my most reliably healthy and happy corals and I went out of town for one day and come home to find a big chunk of it separating from the skeleton. None of the critters / fish in my tank have ever touched it in my observations. Any idea why this is happening? It still looks like it's going for full extension today in spite of this very significant looking damage.