So I have the dash vents on with the heater control ….the SYNC button is lit....heat set at 20 degrees...its 16 degrees below zero outside.....the vehicle is up to operating temperature. The drivers side vent is blowing coolish air and the passenger side is blowing hot air. I disengage the SYNC button....turn the drivers side temp up to 26 degrees and leave the passenger side at 20 degrees. The drivers side continues to blow cool air and passenger is still hot. Something is amiss....anyone have a suggestion?