@Alexandru Moldoveanu , can you tell us if the mark on the obverse is raised or recessed? It looks like a scratch to me. Chris
The absence of the designer's initials could be caused by mint over-polishing or just excessive wear.
I don't know what you mean by, "....it is not dip." The lighting can play tricks on you, especially when you are using a microscope. Try rotating the coin a bit under the light. FWIW, it looks like a genuine FS-901 to me. Chris