Jira: https://jira.unity3d.com/browse/GFXGI-509

Steps to repro:
1. Open the attached project and SampleScene scene;
2. In the Lighting window (Window>Rendering>Lighting) click on the dropdown list on the Generate Ligthing button and select Clear Baked Data;
3. In the Lighting window press Generate Lighting button;
4. In the Hierarchy select GameObject gameobject;
5. Observe the selected reflection probe in the Scene view.

Expected result:
Reflection probes contain indirect lighting from the emissive cubes.

Actual result:
Reflection probe is partially black and doesn't contain the indirect lighting. See attached screenshot.
Regression introduced in Version 2020.2.4f1

Workaround is to bake reflection probe individually in the Inspector or bake with enabled progressive updates or in auto-baking mode.

Notes:
- Reproducible in Version 2021.2.0a10, 2021.1.1f, 2020.3.2f1, 2020.2.7f1, 2020.2.4f1;
- Not reproducible in Version 2020.2.3f1, 2020.1.17f1,
- Not reproducible with Progressive Updates are enabled in the Lighting window;
- Not reproducible when the auto-generate GI checkbox is enabled in the Lighting window; reproducible only in on-demand manual GI bake mode;
- Reproducible when baking with CPU and GPU Lightmappers; not reproducible when baking with Enlighten;
- Reproducible in both Editor and Standalone player.
- You might need to clean the cache, if the probe can be found in the cache it will be loaded from there.