From a materials point of view the hot plastic note comes from binders and release agents flashing off and the nonstick polymer finishing its cure but then it is not unusual in the first few uses and it usually disappears once those volatiles are driven out.
You can speed it up with wet heat and gentle oil seasoning. After a thorough scrub run a that model minute cycle with a cup of hot water and a splash of vinegar in a small oven safe dish so the interior steams. Let it cool, then lightly wipe the basket and crisper with a teaspoon of a neutral oil, heat 5 minutes, cool, wipe dry. Do not slather oil or it will smoke.
If the odor is acrid or gives you a headache, stop using it and check that nothing is melting around the heater, no tape stuck near the element, and no drips are hitting the hot metal. Otherwise plan on three to six good cycles and it should be fine. Patience helps.
