Preheat a 6-quart air fryer to 400°F for 3 minutes. Pat chicken dry and toss with salt, garlic powder, pepper and cornstarch, shaking off loose starch.
Toss gently with oil and arrange half the pieces in the basket in one layer with gaps. Air fry for 5 minutes, turn and cook for 5 to 7 minutes more until lightly crisp and at least 165°F.
Transfer to a clean bowl and repeat with the remaining chicken. Meanwhile, warm hot sauce, butter and vinegar in a small saucepan until the butter melts.
Toss both cooked batches with the warm Buffalo sauce just until coated.
Rest for 2 minutes and serve immediately while the edges still have texture.