how about you stop trying to "grind out bosses" every other minute. It works best when you wait 5 to 10 minutes after you use one for Vanguard streaks in Strike playlist. Works for me everytime. I still use them and I recently use them at the beginning of the strike then I either get a bunch of legendaries or an exotic engram. Exotic engrams are still not always what I want but HEY, I just got a 310 jade rabbit recently (PS4)