This quote is deep in a thread in "General..." and I thought dedicated "Project Finishing" readers should benefit from it too so I'm quoting Tom King...
So that's flat sawn with the heart side up. Moisture content is always changing in wood. The top got dried and the bottom may have picked up a little...
Edward's suggestion seems like the way to go, a magnet on one side only and a washer on the other. You can reduce the grip and the snapping noise by...