Green star polyps closed

[Fish3]

Hello, I am new to reef keeping and started off my reef with pulsing Xenia and green star polyps. I recently added some hammer coral and zoa’s to the aquarium and they seem to be doing alright along with the xenia but my greenstar polyps have closed up since the addition of new coral. I have provided some before and after photos. How do I fix this? Is the hammer coral too close?
Thank you.

 

[revhtree]

Green star polyps are notorious for closing up for an extended period of time!

Do you have any fish that might pick at it though?

 

[Fish3]

Green star polyps are notorious for closing up for an extended period of time!

Do you have any fish that might pick at it though?

Thank you for your reply! The tank is 15 gallons stocked with 1 clownfish, three Trochus snails, a tiger conch, and a pincushion urchin which is about 1inch in diameter (in there temporarily to be moved into a larger tank when he grows a little bigger) and I do have quite a few amphipods in the tank.