There is a passage where cold air moves between the freezer and the fridge.
When a door on one side is opened and closed, the outside air and inside pressure are pushed into the door on the opposite side, and such pressure causes the opposite door to open slightly and then close.
It is normal that the door is opened slightly and then closed due to air pressure, and you can rest assured as it is not a product defect.
This guide was created for all models, so the images or content may be different from your product.