Cruel Act 3 boss Ignaduk not dropping the spirit part of kill reward

I have leveled multiple characters and no problems before, but for this character the 40 spirit reward is not dropping, despite now killing it three times. I dropped the other quest reward for killing this boss for the charm (Tribal Vengeance I believe it's called), and that has been completed.

I was wearing an amulet with spirit, which I have removed for the image to show that I have 60 spirit and the quest item is no where to be seen.

Bug report reference number: 1 755 754 046