Dragging over a Subdiagram Label breaks drag-and-drop from Project Explorer

This bug has proven to be perfectly repeatable on my system. I'm using the LabVIEW Core 3 Course Project to reproduce:

1. Open the block diagram of a VI with while loop or case structure whose Subdiagram Label is visible.

2. Drag a VI or control from the project explorer onto the block diagram.

3. Drag the VI over a Subdiagram Label, then away from it.

RESULT: Object is ready to be dropped until you drag over a Subdiagram Label; after this the object cannot be placed, as though it is always in an invalid location. See attached pictures.

I'm using LV 13.0f2