condensation between window panes 4

https://apexwindowsglassglassunithouse.silverstonebrief.com/posts/the-right-way-to-handle-glass-unit-replacement-in-your-home

Waking up to find condensation between your window panes is a clear sign that the insulating seal has failed, letting moisture sneak in and fog up the view. It's not just annoying—over time, that trapped water can lead to mold or even damage the window frame. If you see those tiny water droplets pooling inside the glass, it's probably time to call a professional or start saving for a replacement.