In my experience, clouding most likely is moisture got under the finish. The how part needs to be identified and resolved. My dad's browning sxs had to be sent back to the factory to be refinished under warrenty due to clouding. Take a good look to see if there is any way moisture is leaking through a crack in the finish, through an end cap, butt plate, any unfinished non-sealed area, ect. Let us know what you find.