Mine performs the same on CHAdeMo. You are not doing anything wrong.
A local TV journalist made the test and figured it will add 2 - 3 extra liters of fuel to recharge the battery , the price here is around 1.5$ a literHow much gas is needed to re-charge the battery - also at what gas price were the calculations made?
Good channel - I watched all his videos before buying the vehicle.This guy says 94 minutes while parked will charge from zero to 80%.