I finally saw this thread. I hate to be the bearer of bad news, but... I think you broke a front axle shaft.

Low range locks the differential center, hence you can move. In high range, the center is unlocked. Even with QDII, you need wheel sensors for the computer's input, and the free spinning axle won't trigger that since the sensor is on the back of the brake rotor, so you won't get a clutch lockup in the differential. And, all the torque is going to a ''dead zone'' with a broken axle, so you don't go anywhere.