I think the recirculation turns on automatically if the sensors see the temperature differential is too big because A/C with recirculation is the most efficient way to cool the cabin down. If you turn on the A/C when the cabin temp is closer to the outside temp or set temp, it might not come on. I know that the system did turn off recirculation automatically for me at some point while I was doing a long drive with A/C on, but I don't know the exact requirements for the system to do that.

 

Normal.

 

Yep - most efficient / quickest way to cool down the cabin.

 

I think it does this at a preset outside temperature, say 72° or so.

 

that pic's not from your car is it? because that's not a 2018

 

he snipped off this video.

The dust spot matches the pic.

 

I have purchased the same vehicle LE and its very normal to cool it off fast then you can turn it off , but because I rather not have the poluted air coming in I just leave it on and turn the temperature down and the blower at times . the best thing I like in most of my cars is the automatic light setting , you never have to pull a switch on or off . good luck with progress.