Reproduction steps:
1. Open the attached “ReproProj”
2. Open the “/Assets/Scenes/SampleScene.unity” Scene
3. Enter Play Mode
4. Click the button with text “Show MyMaskableGraphic“
5. Observe the Editor

Expected result: The Editor doesn't hang
Actual result: The Editor hangs for about 30 seconds

Reproducible with: 6000.0.67f1, 6000.3.8f1, 6000.4.0b8, 6000.5.0a7

Reproducible on:
Play Mode
Windows Standalone Player

Testing environment: Windows 10 Enterprise 21H2
Not reproducible on: No other environment tested

Note:
- If Scale in Canvas/GameObject/MyMaskableGraphic is set to a smaller value, like 1e+12, the Editor doesn't hang