Moisture Between Window Screen and Glass

The space between the panes was initially filled with a gas that has now escaped and been replaced with air and humidity.

If the screens are on the outside of the window with air between the window and the screen, I'd call the moisture dew. I think the difference in temperature between the house and the outside air causes the moisture to form. That means your double paned windows aren't as insulated as you might have thought.

Because your windows are new, I'd contact the manufacturer.

Best wishes