milky
i used to be a painting contractor. I would use sanding sealer under the varnish, or poly urethane. I did an exterior door once with this combo(the sanding sealer would dry quick so i could sand and top coat in one day). the door turned cloudy in a short amount of time. I had to stip the door and refinish with just poly. Don't know if yours is varnished but if it is they may have used sanding sealer or something like it. I feel your pain the cloudy finish is ugly!