How to make a realistic interior lighting?

Hi, why is the ceiling is so dark, but its base color is white? And how to solve it? Thanks. I’ve never experienced of the “Build Lighting” because when I do it then it takes very long time to build it, and I’ve never succeeded in my life, there are many trees outside that are very CPU expensive.

Does anyone know how to solve this problem with simple method? I believe that it’s very common problem because many people make interior designs.

Edit: Both the SkyLight and Sun are Movable.

The SkyLight has a Setting “Single Color for lower Hemisphere”

Thanks, I renamed the title into “How to make a realistic interior lighting?” to make the subject more general.

I solved the problem about dark ceiling, I changed back the SkyLight mobility into Station then problem solved, but before, I liked to use Movable because it doesn’t have water reflection artifact if I remember but there is no water in this scene,

The next step is to bake the lighting in Blender by using UVs, because as I mentioned, it takes a long long time to build lighting in UE4, but why do other people succeed it? Know that I’m still learning, if someone have an idea how to make a realistic interior lighting, because I saw videos on YouTube and they are amazing, they are not tutorials.