Unity modifying smoothing groups

Hello,
I am trying to preserve the smoothing groups that I have made in Maya.
But when import the FBX meshes to Unity, Unity insists on modifying these smoothing groups.
I have a simple mesh with all edges set to HARD, but in Unity alot of them are smoothed out as you can see in the image below. Any ideas on how to fix these issue? I just need my edges to remain hard in Unity, not asking much.

bump!

Have you tried importing it back in Maya? Also have you look at the normals themselves? Depending on the exact rendering pipeline you use you might be able to just inspect the gbuffer.