I'll probably never see a 12 handicap, so I shouldn't be offering tips or fixes, but I noticed a similar problem. With the short
irons, for some reason it's easier to leave the heel of the club raised when addressing the ball. I'm not sure why. If you swing from that position, crazy things can happen, notably the toe of the club catching on the turf early, twisting the club face around. This may not be what you're doing--it seems pretty basic--but I found that if just took extra care to keep the sole flat on the ground when addressing the ball, it fixed the problem--and that might mean backing away from the ball a bit in the setup.