How to reproduce:
1. Open the attached “IN-135495_customEditorTools” project
2. Open the “SampleScene” Scene
3. In the Scene view window change the tool context to “VoxelContext”
4. Try to select one of the “Cube” GameObjects in the Scene View by clicking on it with your mouse pointer
5. Observe the Scene view

Actual result: The Cube GameObject is not selected
Expected result: The Cube GameObject is selected

Reproducible with: 6000.3.0a4, 6000.3.10f1, 6000.4.0b10, 6000.5.0a7
Not reproducible with: 6000.0.68f1, 6000.3.0a3

Reproducible on: Windows 11
Not reproducible on: No other environments tested

Notes:
- The issue also reproduces when you try to rect select the GameObject in the Scene view
- You can select the GameObject in the Hierarchy window and manipulate it using the custom tool