When a door is opened and closed,
does the other door rattle?
Door can rattle due to air pressure inside (cool air circulation).
Rattling is a normal phenomenon and not due to a defect of the product.
How to check
Door can rattle if adherence of rubber gasket is low. Clean the rubber gasket.
※ When beep sound continues, it is due to defective door sensor.
Contact the service center.