When I set It, either auto or not, It will be warm/hot for a couple of minutes. Then I get almost cold air from the vents and never comes back to hot. Have to raise the temperature. Of course, I turn the heat on when the engine is hot. I don't use Auto much in winter as I'm using the defrost vents.
Tried 22 degrees at Auto today and samething happenned. As soon as the cabin is warn, cold air is blasted through the vents. It's either hot or cold.
Let say you have a car with no Auto climate, you can select medium heat at the lowest speed and leave it like that. You get medium heat, It won't turn to cold air. See what I mean?
Try using a thermometer in the car and see if it matches to what you set it to.
I had a problem a while back. When I set it to auto 74F, the temperature would increase to almost 90F. Then sometimes the system would not work, it would freeze/lock up.
There was a reprogram of the heater system, which fixed the lock up problem.
Now if I set it to auto 74F, the temp will increase quickly to 74F, the fan slows down, then I get luke warm air and it stabilizes at about 80F. Still not fully accurate, but its an improvement I can live with.