Torch not opening

[rongy]

I had this torch (I believe it’s Aussie) for couple weeks, and it only have one large head. it’s been opening fine for first few days, but for the last few days, the right half of it is not opening. Is it splitting or something is wrong? Its skeleton grows like wall

 

[blaxsun]

How's your flow?

 

[rongy]

How's your flow?

Medium to low flow at that area. The frogspawn sits next to it and it’s been opening fine.

The torch used to be in a high flow area, and it’s does not fully open, so I moved it to a lower flow area. It stays like this since then.

 

[rongy]

I have a few indo torches, and they’re all opening fine, so I assume my water parameters are okay, but I will post it here for reference:
Salinity: 1.026
Nitrate: ~1
Alkalinity: 7
Phosphate: 0.08
Calcium: 450
Mag: 1380
PH: 8.2