Reproduction steps:
1. Open the “ReproProject“ project
2. Open the “Assets/Scenes/SampleScene“ scene
3. Observe the Game View
4. Open the “Assets/Canvas.uxml“ Visual Tree Asset
5. Expand “Canvas.uxml” in the Hierarchy section of the UI Builder window
6. Rename “Template Container“ to any different name
7. Repeat step 3

Expected result: The UI labels are exactly the same
Actual result: The UI labels are changed to “Label” and “Button”

Reproducible with: 6000.0.0f1, 6000.0.4f1
Not reproducible with: 6000.0.0b16
Couldn’t test with: 2021.3.38f1, 2022.3.31f1 (due to compilation errors)

Reproducible on: Windows 11 Pro (22H2)
Not reproducible on: No other environment tested