Exchange boss coin box

I looked for a way to exchange the boss coin box on the internet but couldn't find it, after I went around the map I finally met the table NPC (located in the side room of the Green Hair Elf NPC in Clements Mine) but the second time I went to the table NPC I couldn't exchange coins. it says "The table is full of dust. There's a trace of the spot where the coin used to be. Did someone take the coin?"
https://scontent-sin6-1.xx.fbcdn.net...9a&oe=60F5D77A
https://scontent-sin6-2.xx.fbcdn.net...af&oe=60F565A2

I'm used to putting menu items in the right corner under the map, so when I double click it looks like nothing happened

click the box, find the coin, sell it to npc, and yes don't put the items inventory on the edge of the screen, of course you wont see the coin content