Blackboard variable is not selected and context menu options do not target it when right-clicking an unselected item

Steps to reproduce:

1. Create a new project using Universal 3D template
2. Import the attached "MySimpleGraph.cs" into the Project
3. Go to Assets > Create > Graph Toolkit Samples > Simple Graph
4. Open the created graph
5. Click the "+" button to add a new variable
6. Click in the graph window to unselect the newly created variable
7. Right-click on the created variable
8. Observe the opened context menu

Actual results: The variable does not get selected and the context-menu options dont target it

Expected results: The variable is selected upon right-click, and the context menu actions correctly target the newly selected variable

Reproducible with versions: 0.4.0-exp.2 (6000.3.12f1), 6000.4.1f1, 6000.5.0b2, 6000.6.0a2

Tested on (OS): macOS 26.3 (reproducible), Windows 11 and Ubuntu 24.04 (not reproducible)

Notes:

• Does not reproduce on Windows and Ubuntu, seems to be macOS specific