“plastic” note often flares back up with fries because the fine oil mist hits the hot heater shield and cooks any residuals. After it’s unplugged and cool wipe the upper metal shield and walls with a barely damp cloth and a drop of dish soap, then run one more vinegar steam cycle. For the first few cooks, use a perforated parchment liner and run 25–50 degrees lower than max to cut splatter while the coating finishes curing. If it’s still strong after several sessions and it’s reasonable to exchange it rather than fight it in a small dorm.
