Apparently pre-rinsing confuses the dishwasher or something. Not doing it leaves me with residue all over the other dishes though 🤷
Electricity in the usa is not weaker than Europe. Since the voltage is half as high, it just takes double the current to do the same work. A heater running 220v at 5 amps and a heater running 110v 10 amps will work exactly the same.