Mastodon Tusk not dropping

I have fought the required boss 5 times on two separate characters. Both require the tusk as a quest item to progress further but it is not dropping for either of them. The quest is still active and says I need to collect the tusk despite it not dropping. I turned off item filters for this fight as well.

After testing it myself, Killing the Elephant first then the other boss results in the tusk dropping. This also showed a new bug where the boss only dropped the tusk and no other items.