“Attempted to insert duplicate object ID hash <hash> into atlassing lookup map.” error is thrown when trying to bake lighting of Terrain GameObjects within additively loaded scenes

Reproduction steps:
1. Open the attached “Unity-TerainTest” project
2. Open “Assets/_App/Scenes/Default-Scene” Scene
3. In the Lighting window (Window > Rendering > Lighting), press “Generate Lighting”
4. Observe the Console

Expected result: No errors are logged
Actual result: “Attempted to insert duplicate object ID hash <hash> into atlassing lookup map.” errors are logged, followed by “[Progressive] Mismatched instance material bindings.“ error being spammed

Reproducible with: 2022.1.0a1, 2022.3.60f1, 2023.1.0a19
Not reproducible with: 6000.0.44f1, 6000.1.0b12, 6000.2.0a7
Fixed in: 2023.1.0a20

Reproducible on: macOS Sequoia 15.3.2 (M1 Max), Windows 11
Not reproducible on: No other environments tested