That rewind rounds/kinetic tremors roll would not drop for me after many, many useless haunted lost sectors and engrams. I spent hours grinding for it, got nothing and feel stupid and exhausted. I got more shotguns and Jurassic greens (this gun is insta trash) thrown at me than I knew what to do with but the auto was one of the rarer drops for me. I got some repeated rolls too, making me wonder if the bug is still a program... it's this kind of crap which makes me want to leave