There’s no slots missing. I’ve looked underneath and find none of the slots are missing. Thus the object in question may have been something else unrelated to the harp. When I stood the harp up and plucked the problem strings, they still buzz. But when I hold on to the mechanisms inside neck area of the harp in the high octave section, the buzzing stopped. I think there’s something a little wrong with the mechanisms in the neck of the harp. Probably the plates are a little loose or something.