Step to reproduce:
1. Download the package from the link in comments
2. Create a new URP project in Unity2020 or above.
3. In Editor mode, Open SceneA, drag Scene B into it. Right click SceneB and select 'set active scene'. You will see the cube in the camera become white.
4. Next, set SceneA active and enter play mode. Repeat the process to set SceneB active, it is expected to see the cube become white but you will see the cube become darker instead.

Explain in detail:
1.Scene A in the package has set the Environment Light intensity multiplier to 1
2.Scene B in the package has set the Environment Light intensity multiplier to 2
3.When Load Scene B Additive in edit mode in editor the light intensity is set to 2
4.When Load Scene B Additive in play mode in editor the light intensity is set to 0 which is not reasonable.

I also have find out that there is no such issue in build-in pipeline. The issue does not appear in URP when the Environment lighting source is not set to the Skybox.

Workaround is to manually bake Lighting for Scene B in the Lighting window.

Notes:
- Also reproducible in built-in (legacy) RP.