BUG REPORT - SKELETON ORDER RIDDLE QUEST NOT WORKING

Hi, I'm just reporting this bug that needs a fix, I was doing the skeleton order riddle quest on Crook's Hollow, I don't know if it effects the other islands with the skeleton order riddle quest? so what's been happening when I'm about to finish the quest, the treasure wont come up when I'm digging it up from the ground, it makes that chest sound when you dig it up, but nothing is come up. please take look at this. thank you