Fissure Crafter Quest Problem

When my group got to the crafter
He gives us a quest to defend incoming group of monsters

When we have killed all the Shadows and only the Abyssals were left
They were "stuck?" and didn't came to us

So our group eventually went to kill them instead
There were 6 Abyssals

After we killed them and check our quest log
It says we still need to kill 1 more group in order to finish quest...

We tried another run, pulling them more close to the top then slay them. Same problem happened again

Anyone that have sucessfully finished this quest before could tell me what went wrong?

I really want to check those armors for my very own eyes
I would need to finish the quest to be able to craft anyways T_T...

Thx for all the info.

But ah, what's your question?

Why this happend? Easy, it's a bug, try it again.

What the armors look like? I dunno.

My question is:

How do I finish this quest sucessfully?
Tried 3 times already
All failed due to the "1 group left" problem

It's not a bug
the last group is around the temple... just kill all the "Shadows groups" you see

This use to be the problem with the quest whenever I would do it. We would go kill the abyssals and low and behold, the quest can't be completed. Finally we waited a few minutes after killing the shadows. The abyssals eventually came on their own. We killed them and the quest was complete. Maybe the activation timer for them to attack is just bugged.

Through my own experience, I think the following is happening: If you let the mobs get too close to the crafter (eternal forgemaster), he will attack them. If he gets the kill shot in, your quest log doesn't update. This is only based off of 6 or so trips there, doing the quest, but it seems like the times we let mobs get in his melee range were the times that the quest got bugged. So keep the mobs as far away from the crafter as you can, and you should have a better chance of winning.

but none of the mob even touched the crafter T_T
those 6 abyssals didnt even move until we attack them

quite frustrating after 3 tries

still many thx for all the suggestions
will try all those methods