910 D2 Lie adjustment

My driver has the Mitsubishi Rayon Diamana Kai'li stiff shaft. Bought it with the regular but switched because it feels so much more solid. Since my buddies point out that I am vertically challenged in stature, I decided to adjust it to the 3/4 degree flat lie (B1 if I read that chart correctly). I lost about 10 to 12 yards and can not figure out why that would make any difference. I noticed that the setting is on the "open" side of the chart but the ball didn't seem to fly much higher or even more crooked.  Put it back to A1 and all is good again. Can anyone explain this?

Jim Miller
Wadsworth, OH