Yes, you can attach the raw Blender model file in the forum. Use the Attach tool. Is it an FBX? Sometimes settings from Blender do not carry over to UE, or ones that are not correct for UE carry over to it…such as the normals. Blender and UE use different XYZ axis references. In Blender I think it is X and Z are the horizontal planes, while Y is vertical. In UE, X and Y are horizontal, and Z is vertical. During export, you’re able to select which direction each axis translates to in the file exporting. Not changing it probably means that model is exported into UE with the wrong orientation / reference planes, and that would damage / mess up a set of texture UVs. I’m not sure if it would screw with lightmap UVs.
Actually, generating lightmap UVs in Blender, and then exporting to UE, then generating lightmap UVs in UE could become a problem. How, I do not know exactly. You should read up on it or even look for a youtube video. I’ve seen that videos are in youtube search results for it. But a simple set of instructions would be easier, IMO!!!