Lightmap ambient occlusion baking UV question

Hi all,

I am trying to create an ambient occlusion map in Blender following this person’s answer . While I can bake the ambient occlusion map, everytime when I do ‘U’ (/UV mapping) -> Lightmap Pack, it resets my current UV map to some kind of default one. Before and after pics :eyebrowlift::

before Lightmap Pack (just some Smart UV Project mapping and than scaled):