The second one. A bad seal will manifest differently and in another part of the window (where the windows itself meet the frame

Interesting product! Only catch I see is that if applied now the risk of trapping moisture between the glass and the plastic is high. Leading to condensation you can’t remove/dry.

On top of that the window is a 3 pane glass. Pretty much top notch. Don’t think the plastic wrap could solve the problem. I’ll sure try it in my cabin tho!

I’d suggest using a dehumidifier. Alternatively open the windows once or twice a day to reduce the humidity in the room where this is happening.