I don't recall what chirps may have happened, and yes it's quite possible I shut it before it traveled more than 2 inches. I pressed the opener button multiple times (all three of them - fob, dash, and on the door), but I'm not sure what is meant by "unlocked." I hesitate to actually try anything on it right now, but if it ever happens again I'll try it. In this case the automatic open/close was not functioning, and the latch wouldn't latch closed.From reading the manual I think the problem can be recreated by stopping the automatic opening when the tailgate is automatically opening within 2 inches of being closed and a curp will be heard. This should recreate what happened. Did you hear a curp? If this is what happened it can be fixed without tools by following the initialization process.
From the manual
p 150 When closing the rear gate after opening it, make sure to use the power rear gate. If you close the rear gate manually with extra force, the power rear gate may be damaged.
p 156 If the power rear gate detects some abnormality while operating, an electronic chirp will sound and the power rear gate operation will be automatically stopped in either opening or closing position. In this case, the system needs to be initialized in the following order to restart the function properly. p 157 1. Keep pressing the rear gate opener button until it is unlocked. 2. Lift up the rear gate. 3. Pulldownthereargateuntilitstartsto close automatically. The system will be initialized once the gate is fully closed. 4. Operatethepowerreargateandcheck that the function operates properly.