I'm struggling with how the pieces shift around. As I'm dragging a piece across the puzzle it messes up everything else I've done. I'd prefer to have it not aff

I'm struggling with how the pieces shift around. As I'm dragging a piece across the puzzle it messes up everything else I've done. I'd prefer to have it not affect other pieces until I drop it, at which point it swaps places with the piece I drop it on.