Reproduction steps:
1. Open the attached “TestCanvasIssue.zip” project
2. Open the “Assets/SampleScene.unity” Scene
3. Enter the Play Mode
4. Observe the Console window
Expected result: “childCanvas.rootCanvas == rootCanvas: True” is printed
Actual result: “childCanvas.rootCanvas == rootCanvas: False” is printed
Reproducible with: 2021.3.46f1, 2022.3.52f1, 6000.0.29f1, 6000.1.0a4
Reproducible on: Windows 11
Not reproducible on: No other environment tested
Note: Only reproducible if the child canvas is disabled.