Need help with White Zombies!!

[KingNebTheGreat]

Hello everyone. 4 or 5 weeks ago I got a frag of some white zombies, and they did great! for the first 3 or so days. After that and up to now they just never open fully. The most they ever open is like 60 - 70% of the way in the morning and then they close up nearly all the way within 6 hours of the light coming on. I don't believe its that the light is too strong as I got 5 more zoas about 2 weeks ago and they all have been doing splendidly at spots in the tank way above the sandbed where the white zombies were the majority of the time. I dipped them in two little fishies revive before they went in and after they were fully acclimated. I never see any pests on them apart from a bothersome astrea snail from time to time. I'm at a loss for what I should do from here because of the 10 different zoas in the tank, they are the only ones not doing well.
My tank does have some vermetid snails but nothing else that I know of.

Tank parameters
Sal: 1.025 Calcium: 460 Alk 7.8 PH: 8.0 Nitrate: 0 Nitrite: 0 Phos: 0.1 ammonia: 0

3rd photo is the day after I put them in

 

[Mr. Mojo Rising]

Personally I would try a different spot, give it a different perspective of lights and flow. Sometimes it helps, sometimes not. Or wait it out, they don't look bad, possibly still acclimating to your tank. But I wouldn't make any drastic action. Good luck