Isopropyl Alcohol leaves a white haze on plastic, is there anything I can use to clean it off?
Even the common alcohol ( ethanol, ethylalcohol) is known to corrupt surface of some plastics, and rubbing alcohol ( isopropanol, isopropylalcohol) is even better in that, as it contains bigger organic chain and is less polar.

These alcohols do not dissolve the plastics in large extent, like acetone often does, but they may corrupt surfaces, especially if they are shiny or polished.

The typical case is compact polystyren or polymethylmethacrylate, that are often clear and shiny, where the white milky haze is very well visible. The opposite case is filled black shiny plastic where the haze and lack of shining  is notable.

For similar reason, lukewarm water with detergents is preferred for plastics cleaning.

The only way I see to get rid of the haze is polishing, or applying a selfpolishing  coating, if applicable and worthy. Perhaps polishing of wax coating.