Keyboard backlight issue

The keyboard backlight of my MacBook pro-2017 13'' isn't working properly. It is set up so that when I press a key, lights up, but after a short period, some keys stop to respond to this command, while it is possible to activate it moving the mouse or using the trackpad. If I shut down the computer, it starts to work again for a couple of hours and then the problem returns.

I called the Apple Support, but it wasn't very helpful.

I already tried to reset the MSC, restore to original settings and reinstall High Sierra without previous settings and apps. It worked for just 24h then it started again as described above.

It is possible that it is a problem of the new update 10.13.3? Anybody with the same issue?