Add me to the list. Same thing happened driving home on Saturday. 82F outside, humid, driving about an hour on the highway. Noticed the air getting warmer and slower. Even at full blast, the air felt and sounded like it was being restricted. Attempted to turn AUTO on and the mode literally did nothing. Finally shut the AC and recirc off, and slowly over the next couple of minutes, the fan speed started picking up and the "blocked or diverted" sound disappeared. Within 2-3 minutes my fan speed was normal and when I turned the AC back on, it was like normal.
To see that type of recovery within minutes doesn't make sense to me. If the line was frozen, as detailed in the post above, it would have taken some time to thaw out before working again. This feels like the system is trying to block recirculation flow actively. The same type of weird thing I noticed when I was driving one humid morning and the truck randomly turned on the AC on itself (only to find that the truck monitors humidity within the cabin and will run the ac if the humidity gets too high?)
I only have 3300 miles on the truck.