Keyboard remains (faintly) lit after power down

A recent update brought a weird behaviour with it. Nothing dramatic and nothing to be concerned about, but strange: When I power down, the keyboard remains list at the most minuscule level. When I walk past the laptop in the dark, I’ll see it. During the daylight it’s easy to miss.

Strangely enough, if I use Hyper+trackball to change the color and brightness in this state, the light disappears completely and now the laptop looks truly “off”.

I have a MNT Pocket Reform with i.MX8MP Module.

I use the following desktop file to power off:

[Desktop Entry]
Type=Application
Name=Power off
Keywords=Shutdown
Exec=systemctl poweroff
Icon=system-shutdown

So effectively, systemctl poweroff.