Hi, I'm learning to do lightmaps the right way but when I import the model in UE, these darker spots appear from nowhere and i dont know if its because of the lightmap or wrong settings in the editor or both. Please help, thanks a lot

[CRUDK]

I ve already set the lightmap resolution of 128 (isnt that enough? : / )
another guy told me that its a matter of normals/baking …I just used a 3ds max plugin to orient normals on the planes to avoid triangulations (IFW normals Improved Face Weighted Normals | ScriptSpot)

I tried disconnecting the Roughness map node in UE and the stripes (737373 picture) dont show up…what I should do then?