Thanks for the help. Currently it started to work I only had the issue during night time so it can be related to the power settings but I did not find any settings related to the power and keyboard backlite. 
Hello all, I hope you can help me. I have recently bought a Dell G15 5515 Ryzen Edition laptop. Everything was working properly until today I restarted the computer and the keyboard backlight is not working, not even the capslock key. When I turn off the computer and open the lid the lights turn on for a few second but afterwards nothing, and if I push the backlight fn key nothing happens and if I push the capslock key it works but the lights just do not turn on or off. I cannot find any settings and any info about it, in the BIOS everything is enabled and turned on. I did not install any update and any software in the past 5 days and still I have this issue. Thanks in advance for any recommendation.
G15 5515 keyboard backlight not working