Colony of Zoa always closed

[SilkyCoral]

Hey everyone,
I have a colony of zoas that stays consistently closed. It’s not dying or getting smaller but it never opens up.
My LFS says it’s because I have a hippo tang, but I’m not convinced of that so I figured out I’d see what other reasons you guys know of for a colony to stay closed.
I’ve placed it all over the tank for different lighting and flow. Also, doesn’t seem to matter if my parameters are good or pristine.
Cal, alk and ph are always good.

Ideas?

 

[DSC reef]

I would try less flow and lower light for a few weeks. Maybe even try giving it a dip before hand.