Slaughter 3000 stuck mob off map

I have attempted Slaughter 3000 a few times now and a mob keeps getting stuck off the map and I can’t kill him. Can anyone help me here? I have a PS 4 pro ziggster1980

I had the same issue. It’s a PITA… I retried to do it until I could get all the mobs. Had to do it maybe 10 times in total.

I constantly have this happening, every time I went to the 3000 actually, so I bring a few extra weapons. If the enemy is trapped behind a door or wall off the map, such as flyers or newly spawned characters, I use a rocket launcher. If the enemy spawns in but bullets do not work, sometimes they hit invisible ways, I use homing grenades and throw to the sides or under where the invisible wall absorbs the bullet.

If the bosses spawn and you cannot shoot them, it is better to just die and respawn.