I have a MacBook Pro (15-inch, Late 2016). I have 2 Dell U2515H as well as an external HDD attached to the dock that are not being detected. The keyboard I have plugged into the dock is being detected and sound is getting passed through the dock.
The monitors are connected via DisplayPort to mini DisplayPort cables. I have tried connecting the HDD via one of the usb ports, as well as a usb-c port with no success.