Yeah, this one's common. It's almost always the wire rack or crisper plate not being fully seated in its track.
FIX:
Unplug the unit and let it cool. Pull out the drawer. Check two things:
- Remove the wire rack and crisper plate. Make sure no food debris is stuck in the tracks or under the fan at the top of the cooking chamber.
- When you reinsert the rack and plate, push them all the way back until you feel a firm click or stop. They should sit flat and level.
IF THAT DIDN'T WORK: With the drawer out, gently spin the fan blade at the top of the oven by hand (unit unplugged!). It should spin freely and quietly. If it wobbles or scrapes, the fan assembly is damaged.
HEADS UP: That rattling is annoying, but running it with a loose rack can cause uneven cooking and might damage the non-stick coating. Always double-check the seating before you start a cycle.