Try changing them back and see what happens,??. my line of thought is your AWD is independent rear axle, and I am guessing this is not the first rotation on this car, and I am also guessing you may have perhaps over 200,000k, leading me to further guess and say that your independent rear end is not quite right,( perhaps slightly worn independent rear end components, ) or just has worn the tire from over loading,??, perhaps one, a little more than the other, and when you put the rear tires on the front, one of the out of shape tires is pulling the steering to one side, just guessing, I would suggest you change them back asap, and check your steering, if ok, do another rotation, and four wheel alignment and balance, note which if any wheel was out of balance, and keep an eye on the out of balance wheel in the future, ??? again just guessing.