Question? when it rains i see the line where i squeegeed but when it drys

when it drys and is sunny you cant see it its so weird ive been cleaning window for 8 years and never seen this please let me know what you guys think.

I’ve seen similar results with windows that fog up after you’ve cleaned them. They get foggy and you can see a squeegee line but when you open up the window to get some air flow, all traces of lines or whatever disapear. Strange I know.