I saw this while testing my game.
I have a light situated behind the Main Camera. All is working perfect, until I get a Game Over, and changes to the Game Over scene. From then, all lights have no effect and all is darker than usually, even the Game Over Scene (if we zoom out in the editor while playing), and when we play again with the Game Over scene button.
I don't have any light-related script and my light source's properties are:
Indirect Multiplier: 1
Shadow Type: No Shadows
Cookie Size: 10
Draw Halo: False
Render Mode: Auto Culling Mask: Everything
I think this is a Unity bug. But there is a way to solve this?