To reproduce:

1. Download the attached project "rqa-project-grace.zip" and open it in Unity
2. Open "Potential_Bug" Scene
3. Enable Post Processing on "Camera" gameObject
3. Enter Play Mode
4. Observe that Object constantly updates on Render Texture and the Object has a Black outline
5. Exit Play Mode
6. Disable Post Processing on "Camera" gameObject
7. Enter Play mode

Expected Result: Object constantly updates on Render Texture and the Object has a Black outline
Actual Result: Object is drawn permanently on Render Texture every frame and the Object has a Yellow outline

Notes:
- There's also a bug, if you set the "Camera" gameObject Background Type to Solid Color, without the Post Processing option, the whole Render Texture view becomes corrupted in Play Mode
- Outline issue could be related to the Custom Shader, but it's still weird, cause it works correctly with Post Processing
- Videos for reference are attached in the Comments Section

Reproduced on Unity 2022.1.0b1 (13.1.2) and 2022.1.0b4 (13.1.4)
Could not reproduce on Unity 2022.1.0a16 (13.1.1)
Regression on Unity 2022.1.0b1 (13.1.2)