Problem with frames shadows

Hello guys, i am new no U4 and i am having some trouble undestanding what shall i do to improve the shadow quality of my work. in this specific case, the shadows from my window frames as not appearing. Already tried to improve the lightmap resolution the problem persists . What shall i do _ ? the lightmaps seem ok but take a look please . I’ll post the image from the preview and after the light build. Yhank you.

What resolution is your lightmap? You might need something like 2048 for thin detailed shadows like that on a large floor.

What does your mesh and UVs look like?

Like ZacD wrote, it looks like your lightmap resolution is to small… depending on how big your floor is you will need at least a lightmap resolution of 2048 maybe even more…