How to reproduce:
1. Open the attached "IN-151594_EditorBug.zip" project
2. In the Project window, go to the "Materials" folder and select the "TriPlanar" material
3. In the Inspector, set "Surface Type" to "Transparent"
4. Under "Surface Inputs", set "Blend" to a value higher than 4
5. Observe the Inspector window
Actual result: The "Blending Mode" selection box is blank
Expected result: The "Blending Mode" selection box is not blank
Reproducible with: 6000.0.0f1, 6000.0.82f1, 6000.3.23f1, 6000.5.10f1, 6000.6.0b10, 6000.7.0a5
Reproducible on: Windows 11
Not reproducible on: No other environments tested