On your settings, (yours will different to mine as I have the older dashboard) , select heater controls, then choose to get the air coming out of the face level vents only. Then check your getting the same heat through all vents, if not then it could be the control unit is faulty or like Trenchfoot says it could be a crushed hose.
If it the heat feels the same throughout the vents, then all is fine, my vents get nuclear hot on the sides, but very little warm air comes through the centre vents when it's set to auto. If the centre vents got as hot as the sides, it would be more work to get the dual zones to stay at the required temp.
Also only getting higher temp out of side vents is like having central heating under your windows, it stops the cold air around the windows.