Preheat air fryer 360 F for 5 minutes. In a small bowl, mix contents of pickling package with mustard and apple cider vinegar. Place corn beef on a large piece of aluminum foil, big enough to wrap corn beef.
Spread 2/3 of mustard mixture over meat, top and sides. Fold foil around corn beef and place in air fryer basket. Cook at 360 degrees for 1 hour.
Carefully pull back foil, spread remaining mustard mixture on top of corn beef, recover, and cook for another 40 minutes.
Pull back foil, cook at 400 F for 5 minutes to crisp the top of the meat, if desired. Lift out of foil and on to a cutting board. Slice against the grain and serve with cabbage.