Preheat the air fryer to 400°F (200°C).
Pat the steak cubes thoroughly dry with paper towels to ensure proper browning.
In a large mixing bowl, combine the steak cubes, olive oil, salt, pepper, garlic powder, onion powder, and dried thyme, tossing until evenly coated.
Arrange the steak bites in the air fryer basket in a single layer, leaving space between pieces for air circulation.
Cook for 6 to 8 minutes, shaking the basket at the 4-minute mark, until the internal temperature reaches 135°F for medium-rare or 145°F for medium.
Transfer the steak bites to a clean bowl, pour the melted butter over them, and toss with fresh parsley.
Allow the meat to rest for 2 minutes before serving.