Maybe we need an audio of the pop. Like a cork popping? More of a snap? Loud? Soft? high pitch, low pitch? A water drip kinda pop?
If it's coming from the door it's either related to air pressure or something lose. What happens when you close the door with the window open?
If it's coming from the door it's either related to air pressure or something lose. What happens when you close the door with the window open?