SO . I invite you to modify your first comment.
to include (during the purge) it is very important to specify clearly.
and I could only tell you one thing.
The game has a spawn limit for all creatures.
once the limit is reached. the dead bodies of slaves and ennemi disappear.
so I think that reducing the spawn numbers of enemy soldiers could fix this problem.
I also had this problem many times.
I lost a lot of weapons and armor.