How to reproduce:
1. Open the attached “IN-141080” project
2. Open the “TestMaterialModifier” scene
3. In the Hierarchy, expand the Canvas GameObject
4. Select the “FcousLost” GameObject
5. In the Inspector, modify “Radius” or “Border Width” properties of the “Test Material Modifier” component
6. Notice the value gets unfocused and can no longer be edited without retrying
7. In the Hierarchy, select the “NoUpdate” GameObject
8. Repeat step 5
9. Observe the Game view

Actual result: The properties on the script are updated but visual remained unchanged
Expected result: The middle square updates while or when values are changed

Reproducible with: 2023.1.0a3, 6000.0.73f1, 6000.3.14f1, 6000.4.5f1, 6000.5.0b6, 6000.6.0a4

Reproducible on: macOS 26.4 (M1 Pro)
Not reproducible on: No other environments tested

Notes:
- Step 6 reveals part of the issue, of using GetModifiedMaterial
- The middle square is updated when entering Play mode or disabling and enabling either the script or mask components