ASUS Zephyrus G14 keyboard Backlight not work

[seyyoukim]

System: Windows 10 pro
Battery or AC:
Model: GA401IV 
Frequency of occurrence:
Reset OS:
Screenshot or video:
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Detailed description：
My Keyboard Blacklight not work, but when I press Fn+arrow up key it shows on the monitor but the keyboard does not have light.

[Blake_ASUS]

Hi there,
was there any update or modification before the issue occurred?
Also, if you enter BIOS, does the backlight work?
Please load BIOS default setting again and see if it works.
Thank you.