Unable to deselect variables in Graph Toolkit when clicking below or above the element

Steps to reproduce:

1. Open the "GTK_ETs.zip" project
2. Open the "New Graph" asset in Graph Toolkit Editor
3. Create a new variable
4. Try to deselect it by clicking on the blackboard below the element or above it
5. Observe the Blackboard

Actual results: The element is still selected

Expected results: The element is deselected

Reproducible with versions: 0.1.0-exp.1 (6000.3.0a6), 6000.4.3f1, 6000.5.0b5, 6000.6.0a3

Tested on (OS): Windows 11 Pro (25H2)

Workarounds:

• Click outside of Blackboard (other sub-windows also do not deselect the item)
• Press the ESC key