Lighting changes by itself

I am still new to game development in general so easy with the complicated stuff :D.
When I tried to reload the same level again using SceneManager.LoadScene(SceneManager.GetActiveScene().buildIndex);
everything works and the scene is loaded again fully functional, however the lighting becomes a bit dimmer and so everything becomes a bit uglier, what causes this?

The lighting is uglier because Global Illumination is off when loading a level in the Editor. When Playing it in a build it should be fine.

Hi, It may the bug on UnityEditor, see also

You can fix it using the non-“Auto” lighting baking, here the steps on the below:

  1. Open “Lighting” panel on the menubar (Window → Lighting)

  2. Uncheck “Auto” below the “Other Setting” section

  3. Press “Build” to force build the lightmaps

Unity Lighting Bugfix