I have found that USB-A to USB Type-C (sometimes referred to as “Legacy”) cables must contain a 56K ohm resistor. It is required to indicate to the phone/device to fall back to “Default USB Power” when charging from a plain USB A port on a PC/docking station or older charger.
Do the Powerline+ cables contain the resistor?
What does it do when the cable is plugged into a charger capable of fast charging such as a PowerPort+1 port or PowerDrive+1 port?