I have the apple charge cable; and the Anker Powerline USB-C-USB-C cable. Both charge my macbook fine, but neither will charge my Anker PowerCore or M&D MW50 headphones from an apple 61w USB-C power brick. Both the USB-C devices charge from a range of USB-C to USB-A cables. I'm told it's a cable compatibility issue with fast-charge cables. Can anyone explain more, or suggest a 6ft USB-C to USB-C cable that will charge every USB-C device?