Hey Alphawolf154,
I believe what you are experiencing is a light falloff issue. So, in lighting there are ares after a while where the light will start to become less and less bright. If you take a flashlight and shine it in a dark hallway, after a while outside of the cone angle the light will begin to disappear.
A sky light or directional light will provide you with ambient light that will help to fill in these gaps where spot lights won’t reach.
Here is some documentation on troubleshooting lights,
Look through this and then you can start to develop your lighting in a way that you would expect.
Thanks,