Repro:

1. Download and import the repro project (link in the first comment)
2. Open the Scene SampleScene.unity
3. Ensure that the LightingSettings5RealtimGI LSA is assigned
4. Generate lighting
5. In the third room (with the chairs) notice how the room is relatively dark and lit mainly by punctual lights
6. Search-for and select the GameObject "ShadowProxy"
7. Set the Scale in Lightmap for the Object to 0
8. Change the Receive GI: property to "Light Probes"
9. Generate lighting again

Observed:

- When the lightmap scale is 0, indirect lighting from the skybox will leak into the scene. When the Receive GI mode is set to Light Probes, the Scale in lightmap property is hidden, implying that it is not considered. However it appears that it is.

Expected:

- When the Receive GI mode is set to "Light Probes", Clusters should still be created for this geometry in order to contribute to the Scene's GI.

Notes:

- When the Scale in Lightmap property is set to 0, the ShadowProxy does not create Clusters in the Scene. This in-turn means that indirect lighting from the skybox is no longer occluded and leaks in an unexpected way. This is somewhat expected. However the fact that we're using the Scale in Lightmap, even when hidden from the UI is unexpected. We should probably try to find some minimum lightmap scale to ensure that clusters are still created when the object is set to Receive GI: Light Probes.