If your brussel sprouts aren't getting crispy in the air fryer, there could be a couple of reasons. First, make sure they're evenly coated with oil—just a light drizzle will do. Also, don't overcrowd the basket. Give them some space so the hot air can circulate. And lastly, try shaking the basket or flipping the sprouts halfway through cooking. That should help get you that crispy goodness you're looking for!