Stuck in Molten Vault

Got to the final boss in the Molten Vault in campaign and had a long fight before killing the boss at the very end of the room. Noticed I couldn't pick up the quest item because my inventory was full so I opened my inventory to try to make room, but since I had clicked the quest item, I am currently stuck because none of the items are the right size for me to place this quest item in my inventory, but since it's stuck on my cursor and I'm at the end of the room, I cannot drop the item either. So I'm stuck with the item on my cursor, unable to portal out, or move any inventory items. I'll have to wait till my instance times out and re-run the whole awful fight again. I know on controller you get the button to drop an item, but not sure if that gets blocked like the ground loot does here too when manually dragging and dropping

https://imgur.com/a/molten-vault-loot-bug-SLvBwrb

Adding the image's URL just in case it's not visible to others.

After logging back in after the instance reset it dropped the hammer on the ground for me since it had teleported me out of the filled arena so I was able to complete it eventually.