If your corn is tough, you've either cooked it too long or not enough! Corn can become tough when it is boiled in water for too long. The same problem can happen if you leave the corn in the air fryer too long or take it out before it's fully cooked. The best way to ensure that your corn is perfectly tender is to cook for 6 minutes per side. Check for doneness, and cook an additional 2-4 minutes if necessary. Time may vary depending on your corn's size and your air fryer. Always check your air fryer's cooking instructions for the best estimates of time for each type of food.