I have my Komplete Kontrol S61 Mk2 connected to my computer through a powered USB hub, but I also connected it to a MIDI interface for controlling hardware synths in MIDI mode. After a lot of confusion that the MIDI interface wasn't receiving input from the keyboard, I discovered that plugging it in via USB prevents MIDI data from being sent over the MIDI out port. Why?? This means that if I want to use the keyboard to control external gear without turning my computer on, I have to manually unplug the USB cable and buy a dedicated power cable for it. This makes absolutely no sense to me.