Maya FBX export: normals not imported but recomputed/smoothed?

Achromous

I am exporting an FBX (with baked animation) from Maya and into Marmoset, but the normals keep smoothing, even though I have hardened and locked them in Maya. Is there a way to keep the mesh in its hardened state as an FBX? 

(In the picture on the left, is the mesh imported as an OBJ with normals, and on the right is the FBX.)

Joopson

If you import the FBX back into Maya, are the normals correct?
I don't work with animation, but these settings work for retaining correct normals in Marmoset and UE4.

Achromous

I tried exporting with those settings, but it remains smooth, and yes it’s the same when I bring the FBX back into Maya.

EarthQuake

If the normals are getting smoothed when loading in Toolbag, that means the .FBX file doesn't contain normal data. So you'll need to check your export settings to make sure the custom normals are saved. From Andrew's screenshot about, I would try the Split per-vertex Normals option