Hi, what I was referring to was a little stuttering while constantly running and always at the same rate. Yours is not behaving like all others. When holding it or even twisting it, it should not stop for a second and than continue running or catch up: either it´s a loose seconds hand or the movement is dirty (quite normal, it´s why I don´t like decorations).
You could check - with a loupe and amplified detailed pics - if something has come loose. There are glued on fake jewels and fake glued on plastic screws and other parts on it. Best would be to open the caseback with an opener and turn it over a carboard box to see if something drops out.