Camp Liberation lack of spawns

[(XBOX)PracticalSavant]

I've noticed that while I farm for lenses on lower level PoE bounties, there's a lack of enemies that spawn in. I often/always fail these missions. Not because I'm not killing them fast enough, but because there isn't anyone to kill. (Which kinda feels like a meme. "The Tenno can't conquer your outpost if there's no one to conquer it from.")