Okay I couldnt upload all the files but here is a link. The last image where the ceiling gets the light is AFTER I moved so it needs another light build to get proper stuff but after baking the light from the ceiling is removed.
Assuming the lights in your scene are not fully dynamic (Movable), then you can select them in your scene, and within the ‘Details’ tab under ‘Light’, increase the ‘Indirect Lighting Intensity.’ The default value for this setting on all lights is 1.0.
From the first image, it appears the radius of the light does not completely encompass the far wall, therefore it is being illuminated with more indirect lighting than direct lighting. There are also settings you can change within the ‘World Settings’ window within the ‘Lightmass’ section.
For further insight on the settings within take a look at the documentation below as well as the ‘Lighting Troubleshooting Guide’ found here.
Unfortunately I already read those things twice. If you havent checked the link I gave here is another picture. This is a stationary directional light.
Also Talking about the radius of the IES light, this happens when I move it after bake. The prewiev gives better shadows than the baked light. My lights are in production level and the world settings are set to Epic (except anti aliasing and view distance but those are not relevant) just to rule these out.
My directional light have an indirect intensity value 1.2 and the IES light had 1. Are you saying that my objects gets so much indirect light that it overlaps the direct shadows?
Strange I made a new map put less things (to lesser build time) and the lighting worked fine. No more “lets make this object have light and make this get only indirect light”. So I went back to my original map, deleted every light (directional, sky, atmospheric fog) and it still has problems.
However Atmospheric fog made the shadows very blueish and less saturated. When I deleted that and added it again everything worked fine. As I said strange.
I did take a look at your link, and I was suggesting increasing the Indirect Lighting for all of your lights to something around 3 or 4 as this will increase the number of bounces and brightness.
It seems that you have found a project specific lighting issue. I am going to mark this question as resolved, but if you return and find you are still getting incorrect lighting results, let me know.