I just completed it with no problems. I still got “That content has been temporarily disabled” message spam, but I think I have a workaround.
I did everything as quickly as possible. Running straight from green star to green star. And I left all the adds alone.
I believe some of the groups that are off to the side in the cave, are required for the script to progress, maybe, not sure.
I just burned straight through the Grubs, and went straight for the green circles on the map without sidestepping to clear extra trash, and it seemed to work fine for me.
As soon as that green circle appears in the cave, (The green circle that spawns on top of the Engineers that yell for help) I immediately ran back and burned down those adds attacking the engineers.
Hope this helps.