Moritz Halbritter's Personal Blog
After installing Mate, my keyboard backlight on my P50 and my X250 is always on the brightest setting after rebooting. Especially when working in a dark room, this is really unpleasant.
This fixes it:
gsettings set org.mate.power-manager kbd-brightness-on-ac 0
gsettings set org.mate.power-manager kbd-backlight-battery-reduce false
I found it in this forum.