How to reproduce:
1. Open the attached “IN-123650” project
2. Open (Scenes → SampleScene) Scene
3. Select “GameObject” GameObject in the Hierarchy window
4. Enter Play mode
5. Exit Play mode
6. Observe list variable “My List” inside of Script component in the Inspector window
Expected result: “MyList” is resized to default dimensions
Actual result: “MyList” is not resized, as if the space of the runtime-added items is still occupied
Reproducible with: 6000.0.62f1, 6000.2.12f1, 6000.3.0b9, 6000.4.0a1, 6000.4.0a4
Not reproducible with: 6000.3.0a6 (6966ed4b28e1)
Reproduced on: Windows 11
Not reproduced on: No other environment tested
Workaround: Enable project setting “Use IMGUI Default Inspector” (Edit → Project Settings… → Editor → Inspector → Use IMGUI Default Inspector)