I know that normal map issue will never end, so...
I created a lp cylinder and hp cylinder with top edgeloop beveled.
In lp cylinder I set the top edge loop hard (because it's 90 degrees).
in uv I split all hard edges to the separate shells. gave them 1 km padding
duplicated lp cylinder.
locked normals.
triangulated.
exported via FBX with everything unchecked.
I baked NMap in marmoset (tanget space was set to maya. smooth cage). in marmoset it looks flawless.
Imported NMap to maya. set it to Raw aaaaand... looks like vray wants to keep those hard edges on the lp cylinder that I had set before
after this I tried to export with fbx smooth groups, binormals and tangents on an off. same result
set tangent space inside marmoset to mikk. same result
*but rendered with maya software render there are no black edges.
I have nothing left to try...