Not sure on #1. I had my first failure this weekend at an indoor range. But I suspect a dirty mag since it only did it with one mag out of 3, consistently.
On #2, are you hitting high and right, but in a tight group? If your grouping is good and consistent, it's sight picture. You may either not be getting a straight on sight picture, or you may need your sights adjusted.
Also, be sure you're using your dominant eye to shoot. Most people think their shooting hand and dominant eye are the same, but this is not always true. If you don't know how to determine, here it goes:
Extend your arms in front of you with your palms facing away.
Bring your hands together, forming a small hole by crossing the thumbs and fore fingers.
Choose a small object about 15-20 feet away from you. With both eyes open, focus on the object as you look through the small hole.
Close one eye and then the other. When you close one eye, the object will be stationary. When you close the other eye, the object should disappear from the hole or jump to one side.
If the object does not move when you cover one eye, then that eye is dominant. The eye that sees the object and does not move is the dominant eye.
Source: Dominant Eye - Eye Dominance - Determine Your Dominant Eye