Good explanationThe Fan speed and intensity of the air conditioning/heat itself is regulated by the computer. If the temperature inside the cabin is dramatically different from your set temperature, it will blast the AC/heat for a few minutes and scale it back the closer to your desired temperature it gets. Once the cabin has reached your set temp it will have the AC or heat operating at a low setting to maintain the appropriate temperature. Only the light on the auto button will illuminate, and AC light and fan speed indicator will not be in play. If you adjust the fan speed it will deactivate auto temp control.
IDK it makes perfect sense to me. My Ram and Charger both worked exactly the same way, so maybe that's why I wasn't confused by it.....Ac on = light on simple. But that’s not the way it is in the JL with Jeep the AC is running in auto but the light is off so you never really know when it’s on or off in auto. It’s pretty stupid and counterintuitive to me , but I just go with it now.

Except he wasn't referring to a cold day.Don't take this wrong, but that's just silly. Blowing cold air on a cold day no matter what the direction is still a problem.
I seem to have the opposite problem as you. I generally Keep my Auto set on 75. Some mornings when the outside temp is around 70 the Jeep will want to heat the cab up to 75 and I have to remember to turn off the auto before that happens.My bad.....my problem is cold air blows on cold days. He did reference a comment on cold air on a hot day.

Is it blowing cold, or is it relative. I'm not trying to be difficult but I thought my Ram was doing that when I got it (my first vehicle with auto climate). For example, I'd set the temp at 74° in the winter. There was heat blowing for a bit until the cabin temp got to around the set temp. After a while I'd notice a cool breeze and though, "why is it blowing cold air in the winter". As it turns out, I think it may have just seemed cold. If you don't have it blowing directly on you it doesn't feel cool, which leads me to believe it was 74° air blowing out the vent, but on a cold winter day any breeze feels cool.My bad.....my problem is cold air blows on cold days. He did reference a comment on cold air on a hot day.