Did you ever figure this one out?

It looks a lot like Platycodon grandiflora, perhaps ‘Fairy Snow’. Yes, P. grandiflora usually exhibits a 5-part flower and the leaf arrangement is different– but– in pictures of P. g., four-lobed flowers seem to be a normal, though not necessarily frequent– variation. If I’m seeing correctly, I’m seeing a lobed flower and not a flower with four tepals. I can’t think of any other flower that resembles this one other than a Platycodon….. A flower in bud might be the telling thing.
Plants do sometimes vary leaf placement on an odd plant, many times temporarily, so the triad of leaves could be due to some physiological “thing” going on, but the leaves themselves look like a Platycodon of one ilk or t’other.

If I’m right, do I get a prize? :-D