Still not sure about the Solar Roof powered Fan

I've had a 2013 with solar roof for three years and I still don't know if I am using it correctly.

With the button pushed in (on) on a warm day when parked in the sun it does work, usually. I can hear the fan running when I get in the car, prior to pushing to pushing the main power/start button.

I say it usually is running as intended. But I think there have been times when I pushed it, its been hot outside, I've been parked in the sun and it should have been running but I find it wasn't. Somewhere in my reading I've come across that it has to do with what the settings of the temp and venting control are prior to turning off the car. I've read that you can NOT have the fan settings set to recirculate the air. You need to have the button with the icon of the air coming in from the outside set to ON to get the solar fan to work. Is that correct? Maybe I accidentally had the vent settings on recirculate when I had exited the car and that caused it to not work?

Also does the temperature setting have anything to do with whether the solar fan comes on? I doubt it. But I don't know.

Also I've read that it won't work well/efficiently unless the windows are slightly open. I guess if the car is relatively air tight that would make sense to give the incoming air a path to push hot air out. Maybe an half inch to an inch on all four windows?

(It's a cool spring day today and the picture was taken with the car in the garage so ignore the outside temp reading in the picture.)