The cavity of a microwave oven will not leak microwaves without gaps. Just look at the glass on the oven door. The glass on the oven door can't stop the microwave leakage. What blocks the microwave is the shielding net on the glass. The transparent point on the screen is calculated according to the wavelength of microwave, so the oven door will not leak microwave.

Your microwave oven is terrible. Why is the new microwave oven like this? I suggest you return it.