Reproduction steps:
1. Create a new project
2. Install ProBuilder package (Window Package Management > Package Manager > Unity Registry > ProBuilder)
3. Observe the “Create Cube” and “Create PolyShape” tool icons in the Scene window
4. Enter and exit Play mode
5. Observe “Create Cube” and “Create PolyShape” tool icons in the Scene window again
Actual result: “Create Cube” and “Create PolyShape” tool icons change after domain reload
Expected result: “Create Cube” and “Create PolyShape” tool icons remain the same after domain reload
Reproducible with: 6.0.8 (6000.0.0f1), 6.0.9 (6000.0.0f1, 6000.6.0a5)
Not reproducible with: 6.0.7 (6000.0.0f1)
Reproduced on: Windows 11, macOS Tahoe 26.4 (M4)