Window Tint Full Black in Mod Shop

My issue is that I have an addon vehicle whereby when I go into the mod shop, all of the window tints are solid black, they don't have different levels of tint basically. Is there a way to fix this either through zmodeler or other. Note- I don't want to disable the tint completely on the models, just allow them to be tinted. See example - https://gyazo.com/27a20163a57373085d5849a36ea1d645