I’d be looking at the cable capacity resistor. Type 2 untethered cables have a resistor in the plug that signals to the controller what current the cable can carry. Even though with a tethered cable that value is fixed because you always use the same cable, the controller will still be looking for it. There should be a resistor between PP and PE. Standard values are 680 ohms for 20A and 220 ohms for 32A.