Keyboard backlight level doesn't changes to zero, when set in Power Management > Energy Saving.
STEPS TO REPRODUCE
1. Plug in Laptop
2. Change Keyboard backlight in "On Battery" to zero and apply.
3. Unplug Laptop
Keyboard backlight doesn't change
Keyboard backlight turns of
Linux: 5.14.14-1-default (64-bit)
Distribution: openSUSE Tumbleweed 20211102
KDE Plasma Version: 5.23.2
KDE Frameworks Version: 5.87.0
Qt Version: 5.15.2
Thinkpad X1 Carbon Gen 9, Intel
*** This bug has been marked as a duplicate of bug 437715 ***