BUG QUEST

My quest is bugged! I'm stuck on Act 2, Round 2. The boss didn’t drop the quest item, which is preventing me from continuing the game. I’ve tried several times to kill it again, but it still doesn’t drop. I’ve also tried verifying the game files on Steam, but the issue persists. I don’t know what to do now. I’ve been stuck for three days. The quest names are The Trail of Corruption and A Theft of Ivory. Please help me!

wait thing for some help.
MazzCot