Directional lighting completely blacked out shadows

hello i came across a bug and i thought i should let you know. if the directional light is set to moveable when you build the lighting it makes all shadows completely blacked out (no light) in those areas. however if you set it back to stationary and rebuild the lighting. the shadows are back to normal.
thank you

Hi ,

This isn’t a bug. This is a part of rendering in real-time.

When using precomputed lighting (static/stationary) you get bounce light because everything is calculated offline and stored in a lightmap texture assigned to the environment for static geometry.

However, Dynamic lighting doesn’t have dynamic bounce lighting (Global Illumination) without first being implemented. Currently there is no dynamic GI solution that is production ready in UE4. There is Light Propagation Volumes (LPV) and Distance Field Global Illumination (DFGI), but neither is being actively worked on.

To get around this without dynamic GI you can add a skylight to your scene which is like a fake bounce of light.

I would suggest starting here when learning about Lighting in UE4: Lighting Tools and Plugins in Unreal Engine | Unreal Engine 5.1 Documentation

I hope this helps.