Reproduction steps:
1. Open the attached user's Unity project "DX11Bug.zip"
2. Make sure that Graphics API is set to Direct3D11
3. In the Menu bar select Test > ProvokeBug
4. Observe printed Debug.Log in the Console window
5. Change Graphics API to Vulkan
6. Repeat steps 3 - 4

Expected result: Debug.Log prints "Final buffer data: 1 2 3 4 1 2 3 4" in the Console window
Actual result: Debug.Log prints "Final buffer data: 1 2 3 4 0 0 0 0" in the Console window

Reproducible with: 2019.4.36f1, 2020.3.28f1, 2021.2.11f1, 2022.1.0b7, 2022.2.0a4

Notes:
- Issue is not reproducible on macOS and Linux
- Issue is not reproducible with Direct3D12, Vulkan, OpenGLCore, OpenGLES2, OpenGLES3