Is this a throwback?
I've had this Rococco since last summer. It had lovely tight double blooms which looked more like little roses than violets. In the fall I separated a big sucker from it. This left the parent plant with a longish neck so I cut off about half of the root ball and repotted the plant in fresh soil deep enough to cover the neck, as I had learned to do on various discussions on this Forum. A few weeks ago it began to bloom again but two of the flowers are as you see them, neither a proper single violet nor a double. It's as if it had forgotten how to make a double bloom.
What's going on here?