It’s a Mycedium chalice. Someone posted a purple that looked a lot like it, then I saw a FB post from ACI Aquaculture that looks exactly like it. Chris referred to it as Mike the Mycedium. I’m posting a picture from ACI.
I think the ACI one just has a higher density of polyps, if you look at the red eyed purple chalice that is posted on page one, it is the same other than the color. It could possibly be an Echinophyllia, I can’t tell the difference.