Preheat the air fryer to 350°F (175°C).

In a saucepan, combine mixed berries, sugar, and lemon juice over medium heat. Cook until bubbling and slightly thickened (about 5-7 minutes).

Roll out the puff pastry on a floured surface; cut into squares (3x3 inches).

Place a square of pastry in each hand, add a piece of brie in the center, top with berry compote, and wrap edges securely.

Spray the air fryer basket with nonstick spray, place brie bites inside without touching, and air fry for 8-10 minutes until golden brown.

Let cool slightly before garnishing with fresh mint.