Reproduction steps:
{}{}1. Create a new project
2. Create a 3D GameObject
3. Enable Contribute GI Static status in the Inspector
4. Open Lighting window (Window > Rendering > Lighting)
5. Press “Generate Lighting” button
6. Click on 3D GameObject in the Hierarchy and click on Baked Lightmap image in the Inspector (Mesh Renderer > Lightmapping > Baked Lightmap)
7. Observe the highlighted Asset in the Project window
8. Press Baked Lightmap “View” button in the Inspector to open Viewer window and observe Lightmap Asset icon in the Project window

Actual result: Right part of the Asset icon becomes black
Expected result: Asset icon doesn’t change colours

Reproducible with: 2021.3.56f1, 2022.3.66f1, 6000.0.57f1, 6000.2.4f1, 6000.3.0b1

Reproduced on: Windows 11
Not reproduced on: macOS Sequoia 15.4 (M4)

Note: Issue can only be solved by Generating Lighting again