Sounds like you might be leaving the face open when you make contact on a short swing. I've done that before. I even have the proper swing where you are hitting down on the ball and leaving the thin divot in front of where the ball was laying.

Try Dave Pelz's "Short Game Bible". Dave presents the science of the short game in layman's terms.

To summarize his book, you end up working with your wedges (P,S,L,X) and
using 1/4, 1/2, 3/4, and full swings. Even with the 1/4 swing, you still need
to accelerate fully and hit the ball. You can learn the distance with each club and later will be able to stand in the fairway knowing that a 1/2 swing with your PW will give you that perfect 70 yard shot to land within the golden eight foot distance of the cup. This will better your odds of making a one putt.

There are many other topics covered in the book, but the swing techinques mentioned above are my favorite. They have shaved a lot of strokes from my game.