Steps to reproduce:

1. Create a new Unity project using the Universal 3D template
2. Create a new Lit Shader Graph (Assets > Create > Shader Graph > URP > Lit Shader Graph)
3. Open the newly created Lit Shader Graph
4. Hold Spacebar and click the left mouse button simultaneously to open multiple "Create Node" tabs
5. Observe the Shader Graph window

Actual results: Multiple "Create Node" tabs can be opened and are impossible to close

Expected results: Only one "Create Node" tab can be opened

Reproducible with versions: 6000.0.56f1, 6000.1.16f1, 6000.2.1f1, 6000.3.0a5

Tested on (OS): Ubuntu 24.04

Notes:

• The "Create Node" tabs stay even after restarting the Editor
• Does not reproduce on macOS Silicon Sequoia 15.6