The high probability is related to the hinge, and there are two common reasons:

insufficient bearing capacity of hinges: if the window has a large area (for example, the width exceeds 70cm), the glass is double-layer hollow or even three-layer, but it is equipped with ordinary iron or thin aluminum alloy hinges, it will deform and sink under long-term stress.

Screw loosening/wear: frequent opening and closing of the window will cause the hinge fixing screw to loosen, or the shaft will wear and tear, and the window sash will slowly shift.

✅Solution: First check whether the screws are loose and tighten them. If the hinge has been deformed, directly replace the 304 stainless steel heavy-duty hinge (marked with "bearing more than 80kg"). It is not recommended to break it by force, which is easy to break.