Hello all,
Same here, it is pretty annoying, lights stays on when computer is off. Its not big deal, just annoying. (Slider and PC connection LEDs remains ON).
My temporary solution is to always turns computer power supply switch manually. (which I never had to do before).
I have a Korg Micro-Key with some LEDs on it, I don’t have this problem, when computer turns off, the device turns off its LEDs too.
Is there any chance to change this behavior, personally I have a CMC-CH, perhaps a firmware update on the CMS series will be enough to solve this ?
Or maybe a hardware design prevent to change anything about this “problem” ?
Will be nice to read some Steinberg Team thoughts or statements about this 
Thank you,
Best Regards,
Zouk !