Reproduction steps:
1. Open the attached “My project (1)” project
2. Open “Assets/Scenes/SampleScene.unity“ scene
3. In the Hierarchy window add a Capsule 3D Object
4. In the Inspector window change the added 3D Object’s Transform component Position X Y Z axes to be 0
5. Start Play mode
6. Add another Game view tab
7. Place Game view tab below the first Game view tab
8. Rescale any Game view
Expected result: Game view is resized without any stretching
Actual result: Game view is stretched and 3D GameObject gets squished
Reproducible with: 2020.3.13f1, 2020.3.46f1, 2021.3.21f1, 2022.2.11f1, 2023.1.0b7, 2023.2.0a6
Not reproducible with: 2020.3.12f1
Reproduced on: macOS Ventura 13.2.1 (M1 Max), Windows 10, macOS 12.6 (Intel)