Arachnoid mission spawn problems

[tetsensu]

I was running build a better villain arc villain side one of the missions is to kill all arachnoids in a cave mission, I had to reset it 4 times before all the enemies would spawn on the final reload two extra spawns showed up in one of the first rooms, on one reload a spawn that had a set boss on all the other runs didn't have the boss spawn I imagine he was in the walls.

 

Then later on when I was running TV report also redside, I had another kill all arachnoids mission once again in the caves, I cleared all the spawns I could find but I didn't get mission complete so I ran around looking for the last spawns at one point I targeted a group of enemies in a rock and managed to kill them but this wasn't enough to give me locators for the rest of the missing spawns and it was too late for me to want to reset and rekill the mission again.