Why does the keyboard not shine at full brightness?

Question

Keyboard

Laptop: asus tuf gaming fx505dt

I have had this problem since buying a laptop, but I just got to this problem)
The fact is that when I turn on the laptop, I see a fairly bright backlight, supposedly 100%, but when the lock screen appears, all this brightness is reduced by 50% percent.

I installed the Tuf Aura Core keyboard program, and even there I saw a slider displaying keyboard brightness, which showed 33%, but the strange thing is that even if I put 100% in this program, then everything will remain the same

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