stylophora not extending

[fishnplants]

got a piece of stylophora little while ago, bottom looks great but some parts of branches the polyps are either white or wont extend, whats goin on? is this normal?
can post more photos if need be.

 

[Dburr1014]

White, not enough light to get underside.
This guy tho looks to be not doing well. Kinda stn by the looks.

 

[Dingo]

Yes, it’s typical for this stylo to be closed up once in a while. If it does it more often than not then something is bothering it. But this stylo is one of the most hardy out there so if you keep params within check it should not have any issues.
It will be larger than a football before you know it!