I did not say anything in my post regrading explosive arrows. I said it wasn't fixed as it hasn't been moved to boss engrams like every other item that can't be use before unlocking it. Please read the whole post before replying in future.
It isn't "fixed". If it was a bug the engram would of been moved to boss engrams so it was like every other item you can't use before you unlock the engram. It is now the only item in the game you open from leveling that you can't use before you unlock it. Either allow people to use it or move it to boss unlocks so it is consistent with the rest of the engrams in game