Recipe(tried): freezing ravioli

Do you have them wrapped in freezer bags, with most of the air removed ? I double wrap things, and sometimes wrap the entire package of foods in heavy duty foil on top of the plastic wrappings.
Also, if you are freezing in a frost free freezer, they can get freezer burned or "off" quickly. A frost free freezer actually slightly defrosts not only the freezer, but the food stored in the freezer. They cycle on and off all the time. That dries the food out quickly. The freezer compartments in a fridge are the worst. They are only meant for short time storage of foods. So, it could be your freezer.
It could also be some type of herbs you are using in the ravioli.