Help Why my zoa look like this

[MrZ3no]

I have 4 zoas and 3 of them are doing fine except one colony, each day that passes some of the polyp closes up, It was fine in the beginning. I’ve had them for about 1 month now. What can I do? can someone help identify the issue .

 

[Gumbies R Us]

Bumping your post!

 

[Zoa.Mania]

it's a bit hard to tell by this shaking video, but the left part of the colony has some brownish cover on the polyps.

I think it's a bacterial infection (not sure tho). I also get it from time to time. sometimes it passes on its own (some other times it spreads and suffocates the colony and they die) so I would rather dip the frag in h2o2 dip