Steps to reproduce:
1. Create new Unity project
2. Open Package Manager window
3. Install Behaviour package (com.unity.behavior)
4. In Project window create Blackboard (Create > Behaviour > Blackboard)
5. Open Blackboard window
6. Create any Variable by pressing “+” at the top right (GameObject for example)
7. Right-click on the Variable
8. Observe the menu
9. Or try copying/pasting Variable using keyboard shortcuts (CTRL+C/CTRL+V)

Actual results:  Unable to copy or paste/duplicate Variables in Blackboard using menu items or keyboard shortcuts

Expected results: Able to copy or paste/duplicate Variables in Blackboard using menu items or keyboard shortcuts

Reproducible with versions: 1.0.13 (6000.0.62f1, 6000.2.10f1, 6000.3.0b9, 6000.4.0a4)

Tested on (OS): Ubuntu 22.04, macOS Silicon, Tahoe 26.0 (M1)