To reproduce this use the following code snippet:
Steps to reproduce:
1. Start a new connection from Shape 1, by dragging one of its connectors.
2. Drag the connection over Shape 2.
Expected: The connector closest to the mouse should get highlighted and when you drop the connection it should get attached to the shape.
Actual: The closest connector is not highlighted. Also, when you drop the connection over the target shape it doesn't get attached.