I'll repeat this since you didn't answer my question. Do you live in a humid area? If there is no air ventilation in your garage your clothing could be getting mildew/mold from the humidity. (Especially leather items)
sorry lol, I was just reading the movie section,
no my jackets are not leather, they are just like polyester and just cloth material,
so I guess I need a lot of air ventilation for the garage? open the garage and get a couple of fans in there?