DIAGNOSIS The presets are just time/temp combinations. If they're off, it's likely because you're not preheating, or the amount of food is throwing off the timing.
FIX Always let the unit preheat. For the Dual Blaze, that means setting your time and temp and letting it run for about 3 minutes until it beeps, indicating it's reached temp. Then add your food. Also, don't trust the preset times blindly. For frozen foods, always add a few minutes. Shake or flip the basket halfway through.
IF THAT DIDN'T WORK The temperature sensor might be out of calibration. You can test this by running it empty at 350°F with an oven thermometer inside. If it's off by more than 25 degrees, contact Cosori.
HEADS UP The presets are starting points, not magic buttons. Air frying is still cooking—you gotta check on your food, especially the first few times you make something.