My new trailer has two emergency exit windows in the living area. They are the kind designed not to open except in emergency. They have two red latches on the bottom of each window. I noticed one window was not completely sealed against the trailer. Inside the latches on the base are two screws in the base that keep the latch in adjustment. I found one of those screws completely stripped so the latch would no long hold it's adjustment and had loosened to allow the gap between the window and the trailer. In addition, the arms that hold the tension on the latch to keep it closed were bent.
I was able to straighten the arms of the latch - really flimsy aluminum. Then I replaced the stripped screw in the base with a machine screw of slightly larger size that threaded into the base tightly. Then I was able to properly adjust the tension on the latch so that it operated properly.
If you have the type of emergency window that is able to be opened normally using an arm in the center of the bottom of the window, you need to make sure that arm is completely latched into it's holder when the window is closed. If it isn't completely inserted in to holder for it when the window is closed, it's possible that arm popped out of the holder, the window opened, and that operating lever skipped over the little notch that holds the window open for ventilation.