Now that's is weird. I moved from 4.23 to 4.24, and now I cannot change the Lightmap UV index. The objects that I added when using 4.23 are working fine, and if a create a new project on 4.24, it works fine, and I can change the index, but in the converted project, If a re-import an FBX, I got stuck at index 1, even though I do have a second UV, or even with auto UVs on.