My BMW X-3 has something strange going on with its AC. No matter the temp it’s set to, the air coming out starts cold, then warms. The odd thing is, when I set the air mixture to come out on top (windshield) its hot, but if I then turn on the vent aiming at the driver and passenger, that is ice cold. I am told it could be the HVAC actuator or sometimes called the heater blend door actuator. Any thoughts?