I simply cannot switch off the keyboard illumination. If I deactivate the illumination in the Options software, it also switches off, but as soon as the keyboard goes into "standby", the illumination switches back to hand recognition. But the software still says Disabled. The only thing I can do to switch the backlight off again is either to switch the keyboard off and on again at the switch or to switch the backlight setting in the software to hand detection and then deactivate it again. Everything else does nothing (restarting the PC, disconnecting and reconnecting the USB dongle, restarting the software). The lighting just doesn't stay off. I have already tried the whole thing on another PC and it behaves exactly the same. What am I doing wrong?