Reproduction steps:

1. Open the attached project “ReproProject“
2. Open the scene “SampleScene“
3. Try to drag and drop the script “TestScript.cs“ from the Assets to the GameObject “GameObject” in the Hierarchy
4. Select “GameObject“ in the Hierarchy
5. Observe the result in the Inspector

Expected result: Inspector elements are rendered once
Actual result: AddComponent button is rendered twice (also the Layout Properties footer is rendered twice if a component, such as the Horizontal Layout Group, adds the footer in the Inspector), stacked on top of each other

Reproducible in: 2022.3.39f1
Not reproducible in: 2022.3.58f1, 6000.0.38f1, 6000.1.0b6, 6000.2.0a2
Fixed in: 2022.3.40f1

Reproducible on: Windows 11
Not reproducible on: No other environments tested

Note: The script “ComponentEditor.cs“ contains the code that triggers the issue