Phone [Q] HTC 8S Brightness problem after replacement LCD

I have replaced the LCD assembly of a HTC 8S, however, the brightness of the phone is not changing with light sensitivity, nor when I go to settings and change the it to Low/Medium/High.

The lightbox seems to work, however, like said previously, it doesn't change its brightness.

I have already cleaned the contacts with alcohol so no dust should make a false contact.

I wonder if it is some secret setting or it is just a factory error and I need to replace it or some strange HTC thing... I am not familiar with HTC or Windows phones.