The fact that the Moon was low in the sky may have been a factor in your perceived lack of sharpness as you've viewing it through a lot of atmosphere, and this time of year when it's warm there tends to be some unsteadiness in the atmosphere. What's also not helping is at full moon it's being lit face on. It's on a par with taking a portrait photo with one large light straight in front of the subject. Try again when the Moon is higher in the sky and not full, so you've got some sidelighting picking out the craters and mountains. Autofocus should give you a good result but make sure you're on single point focus and the point is on an area where there is a bit of contrast to pick up on.