I had this happen to me on one leg of my 3600 mile road trip a couple of months ago. I thought my AC went out, but my wife started Googling while we were driving and said that the battery can steal cooling from the cabin. We stopped for lunch, threw the car on a L2 charger, and literally as soon as I plugged the car in, the air conditioner kicked on and cooled the car within 2 minutes. We ate lunch, and by the time we were finished and pulled away, everything was back to normal. The following legs had no issues.
There were zero indications on the car that it was doing it... I think it can just happen.
I did have the service center check it out, but nothing came up.
Operating as designed, and hasn't happened since.