I was doing some patrol missions on Mars the other day. I noticed that on three or four different occasions when I killed a Cabal Phalanx and or a Cabal Legionary, after their body hit the ground, an engram popped out and landed where they were laying. Those engrams disappeared to another dimension of some sort. I lost two blue engrams and a green or two as well. I hope that this will be looked in to at some point, I would really like to go back to Mars one day.