I was in this mission with a team that was sniping borg and then all of a sudden it said the optional objected failed. This was very early in the match and none of us entered the room or got close to entering the room that the crewman was assimilated in. Is their a trigger that when a specific number of Borg from a area die the drones start to assimilate crewman or is it a bug?
This was not the first time it has happened it has happened once or twice before.
There's no bug with optional objective in this mission. There are several possibilities: someone in your team doesn't know well the trigger lines, someone made a mistake and doesn't want to admit it (happens quite a lot in premades), or the whole team doesn't know well the trigger lines.
It was very early in the game so time did not run out and no one was even close to getting in the room I know because I was the closest to the room but still far from it. I do not know what happened.
I just google the mission and on stowiki it said some people have claimed that officers get assimilated too soon.
That's not it. The triggers are very sharp though. As i mentioned earlier, look in the foundry missions for "STF" and you'll find a training mission which shows where the triggers are and gives advice how to proceed to get optional.
Just to reiterate what others have lready said, the tigger lines extend the full length of the walls, not just the doorway. And they are on "your" side of the wall. So it possible that when clearing the first room, someone got too close to the wall while still being a distance from the doorway
None of use got near the wall or anywhere close to the room that the crewman was assimilated in because we all stayed as far back as you can get wile using sniper shots. I was in the front and the moment it let me snipe I stopped and lured drones to me. It should not of started a trigger unless a trigger involves a certain amount of borg being killed. So far I have gotten the optional twice once on normal and once on elite and their have been times that people have gotten much closer to the room without a problem of the drones being triggered to start assimilating.