I set the keyboard to be backlit using xset led on. But recently, at the lightdm login prompt when I start typing the password, the light goes dark. After I log in I can reissue the xset command at the command line and the keyboard is backlit again for the duration of the session. I have the xset command in two places now (the 2nd is a more recent attempt):

/etc/lightdm/lightdm.conf.d/50-kb-backlight.conf

[Seat:*] greeter-setup-script=xset led on


/usr/share/lightdm/lightdm.conf.d/50-kb-backlight.conf

[Seat:*] greeter-setup-script=xset led on


How can I get the keyboard to be lit continuously on boot?