This can happen if your air fryer has a forceful fan. I tested this recipe in a Cusinart toaster oven style air fryer and a Cosori 5.8 quart air fryer and I didn't have an issue with the kale blowing around. If it happens with your air fryer, you can lay a metal rack or trivet over the chips. This will prevent them from blowing around but also allows air to circulate so they air fry evenly.