I'm trying to get a mechanical USB-C keyboard working with my MBP so I can just plug in a USB-C cable to the MBP without having a USB-A to USB-C dongle adapter in between. So far I've tried four different USB-C to USB-C cables and all will only power my keyboard but not transfer any data. There is nothing wrong with the keyboard as it works perfectly fine with USB-C to USB-A cable and the afore-mentioned adapter. What cable do I need to get this working? Are there some special requirements for USB-C cables with the MBP?