Keyboard Accessible Drag and Drop

Hi there,

I've found a weird bug in my course. Everything works as desired if the user physically drags items: incorrect, correct, and activity incomplete layers all are working as expected.

However, if using keyboard controls, if you click each item and click their target, I receive the incorrect and correct feedback layers if the items are all correct or incorrect, but if there are two incorrect items and the rest of the items are correct, it is showing the incomplete activity layer. 

The activity is attached, items are numbered 1-6 and their corresponding correct targets are also 1-6. I appreciate any insight!