We gave our grandson a wristwatch as a Christmas present a few years ago. This week he said it was running fast sometimes and sometimes it was slow. Told him I would look at it. As I watched it run I noticed if you held watch with dial at 90 degrees to the floor the second hand would jump at three o’clock. If you rotated watch crown over to other side then the second hand would jump at 9 o’clock. Took it apart, cleaned and oiled it but still did same thing. Thought about it for awhile and saw the original second hand had a large triangular point on the end. Changed hand to a smaller one and now it runs smooth. Watch has An asian movement in it. Never saw anything like this. Any ideas of what actually might be wrong?