Blueprint graph stops drawing correctly after using shift-drag

When shift-dragging in the Blueprint graph and ending the drag on a node with a connected wire, the Blueprint graph will freeze up. There is an attached video that showcases the issue as well.

This was reported and tested in 4.20.3 (CL-4369336). This was reproduced in 4.21.1 (CL-4613538) and Main 4.22 (CL-4670176)

1. Open the UE4 Editor and create a ThirdPerson project
2. Open the ThirdPersonCharacter Blueprint
3. In the Blueprint graph hold down the shift key, click and hold the left mouse button to highlight a few blueprint nodes. End the shift-drag on a blueprint node with a connected wire

Results: The line you finish on is stuck highlighted and every other line is dimmed. Various operations stop working correctly until you refresh the graph by recompiling or placing a comment node.

Expected: The nodes just highlight as normal