How to reproduce:
1. Extract and open the attached “IN-130594.zip“ project
2. Open the “Assets/Scenes/Comparison.unity“ scene
3. In the Hierarchy, right-click the “Sphere” GameObject
4. Click on “Export glTFast → glTFast-Binary (.glb)”
5. Save the file in the “Assets” folder of the project
6. Right-click the “Project” window and select “Refresh”
7. Drag the exported .glb file into the Scene near the original “Sphere“ GameObject
8. Observe the Scene view

Actual result: The re-imported sphere is excessively smooth and glossy, and the unique alpha-driven patterning/modulation is missing
Expected result: The re-imported “Sphere” GameObject looks identical to the original, maintaining the hex pattern

Reproducible with: 5.0.4, 6.15.1 (2023.1.0a1, 6000.0.66f1, 6000.3.5f1, 6000.4.0b5, 6000.5.0a5)

Reproducible on: Windows 11, macOS 26.2 (M1 Silicon)
Could not reproduce on: No other environment tested