Steps to repro:
1. Pull the Sponza HDRP project: https://ono.unity3d.com/test-data/gi-tests/SponzaHDRP and sync to the revision 9ffcf594acd6;
2. Open the 'Sponza' scene;
3. In the Project folder find the 'SponzaLightingDay' scene and drag it to the Hierarchy;
4. In the Hierarchy double-click on the 'SponzaLightingDay' scene;
5. In the Lighting window ensure that the Progressive GPU lightmapper is selected as the baking backend;
6. In the Lighting window press 'Generate Lighting' button;
7. Wait until the baking is completed;
8. When the baking is completed, click on the dropdown list on the right side of the 'Generate Lighting' button and select 'Clear Baked Data';
9. In the Lighting window press 'Generate Lighting' button;
10.During the baking move the viewport in the Scene view (by dragging the right mouse button or scrolling the mouse wheel).

Expected result:
GI bake finishes without errors.

Actual result:
The error:
NullReferenceException: Object reference not set to an instance of an object
UnityEditor.Rendering.HighDefinition.HDBakedReflectionSystem.Tick (UnityEditor.Experimental.Rendering.SceneStateHash sceneStateHash, UnityEditor.Experimental.Rendering.IScriptableBakedReflectionSystemStageNotifier handle) (at Library/PackageCache/com.unity.render-pipelines.high-definition@10.1.0/Editor/Lighting/Reflection/HDBakedReflectionSystem.cs:339)
UnityEditor.Experimental.Rendering.ScriptableBakedReflectionSystemWrapper.Internal_ScriptableBakedReflectionSystemWrapper_Tick (UnityEditor.Experimental.Rendering.SceneStateHash deps) (at <bd5493fc3cac4e0ca13e04a4b569b9a7>:0)

is shown in the Console. Se thee attached video.

Notes:
- Reproducible in 2020.1.0a4/HDRP 10.1.0; 2020.2.0b10/HDRP 10.1.0, 2020.1.0/HDRP 8.2.0
- Not reproducible after disabling the Reflection probes gameobject and rebaking.