Early on in the game, I received the Rebel Recruitment Flier drop from an enemy which initializes the quest “Recruiting Rebels!” At the time, I wasn’t interested in doing the sidequest so I proceeded to trash the item from my inventory.
I’ve returned to the location where the flier drops to complete the side-quest and began farming enemies for hours for it to drop. It no longer is dropping from the target enemies.
I’ve checked my quest journal and I have not completed the corresponding quest so it should be dropping.