There could be a couple reasons why your food isn't getting crispy when using an air fryer. First, when misting with oil be sure not to use too much. Oversaturating the breading will result in it being soggy and the breading possibly falling off. Second, you may be putting too much in your air fryer at one time. You want to have an even layer of food and make sure that things are not piled on top of each other. This allows the air tp circulate and cook the food evenly and makes it crisp up better.