Headshot kills not counting in coop mode for the scoped trophy

So unfortunately, I will not be able to regress this bug against the current version of the game, as I was able to unlock the Trophy through the other Multiplayer modes (I think I was playing Strike when the Trophy popped). I should note that the progress is tracked for all headshots with longblaster rifles, as I got it with a hip-fire (no scope) shot. Good luck to everyone still hunting this Trophy/Achievement.