Lullaby island Magick Melody Co-op quest

I experienced a bug on magick melody quest were after i played the song i left early the first time i did the quest and didnt loot the chest because i walked out before it spawned. when i came back in to retry the quest the chest was there and gave loot but no voice. chest didnt respawn after the 2nd time doing the quest. i whent back in a third time no chest played the song said i completed the quest but was unable to recieve loot. will try a fourth time 2 see if it fixed it self.