Preserve UVs not working

Unity Engine
1

For my model I unwrapped my second UV set in Maya.
I uncheck “generate lightmap UVs” in the prefab import settings.
But Unity5 doesn’t respect that and rearranges the lightmap UVs as it pleases.

How can I force Unity5 to preserve my second set of UVs for my model?

2

in the lighting tab, you also have to check preserve UV, otherwise Enlighten will reorganize your uv shells