After driving my truck for over 50,000 miles and having this issue on a regular basis I can pretty reliably recreate it. It happens most often when it's hot outside and the AC is on, and I accelerate or otherwise stress the engine (going uphill, pass another car). HVAC seems to go into recirculation mode (even though the light for recirc does not come on) and then just hangs there - forever.
I just did a trip from Georgia to Michigan and back (in 80-90 degree weather) and the issue would occur multiple times per hour. It really does get very old, very fast.
I posted a screenshot of a Star bulletin over a year ago that detailed the complaint. It stated they would issue a fix at the end of Q2 2020, but as far as I know that didn't happen.