Birds nest problem

[Fishfinder]

Any ideas what's wrong with my birds nest? The whole thing is growing very good. The left half has great color and growing way faster than the right. The right half of it is very pale. It's growing but barely. The right side has been getting paler over the last 2-3 weeks. It's not affecting the left half. It's almost like one stalk is dying. Any ideas?

 

[mega]

Birdsnest tend to be picky IME, have you moved it around in the tank at all? Or changed anything?

 

[Fishfinder]

It's been there since day 1. Nothing has changed with the tank. Everything is the same as always