By any chance were you using a UAV terminal in your mission? I forgot that, at least with the vanilla gear, if you don't manually deselect a UAV it will remain an active spawner, even upon closing the terminal and going about your business.

If you deselect (UAV terminal, choose ----- or whatever the "none" option is) it no longer spawns. I tested this with the Praetorian, assuming the mod you mention builds off/inherits from it? Otherwise must be something peculiar to the mod :(