Problem with "Generate lightmap UVs" when baking lighting

[dclares]

Hello:
I have a problem with lighting when activating the “Generate Ligthmap UVs” in the import options of the fbx model. I did the test to bake the lighting with this deactivated and activated and the result is too different, for the option of “Generate Ligthmap UVs” deactivated I get the correct illumination, but that is not good due to the overlap of the UVs and optimization issues the uv spaces they occupy are very small, to solve this I activate the option of “Generate Ligthmap UVs” but when baking the lighting it is not done correctly and when checking the lightmaps these are empty, and the scene does not light up.
Here are some images with the two examples, one with the “Generate Ligthmap UVs” activated and the other deactivated, in the upper part it is the Baked Lightmap viewer.

I am using Unity 2019.3.11f1 pro version.

“Generate Ligthmap UVs” OFF

"Generate Ligthmap UVs" ON

[JenniferNordwall]

Hi, are you sure you rebaked the lightmaps? Can you share your settings for the scene? And maybe a flat screenshot of one of the lightmaps? Thanks

[dclares]

yes, the image below is with the baked lightmap but it has no baking information, I found a solution outside of unity and so it works well, what I did is create a second set of UV in the 3d software I use and unity uses this second UVset for the lightmap, so they are baked correctly.