It depends if the mug says microwave proof then put it in but if not do it at your own risk.
Is microwave supposed to get vapar in between glass door.
The microwave is in a cold room then water vapor that has been released during microwave heating cooking could condense on the glass.
Neither of those seem like ways a stinkbug could get between the two panes of glass because i would assume the inside of the door is designed to be sealed airtight to protect from microwaves.
Use the vent fan to help prevent moisture from building up.
There are air vents in the door that allows air to flow between the panes of the window in the door.
The hinges and the clamps that close when the door shuts.
But in most cases this.
If the microwave s glass is cold i e.