Just like 3oC drops are not guaranteed, neither are the NF drops! RNG!!! I've been getting a 1 in 5 drop rate on 3oCs... That's 6 exotics from the 31 coins you got! I don't see your issue?! Try some strange coins + a blue chest engram which is what I got from one of my NF drops! IMO the RNG in Y2 is much better than in Y1... of course there can be some improvements... but I much prefer current state from RNG in VoG way back when!