Eyebrella disappears when dropped

Hi! I was on a boat, a had just killed Crab King. I dropped my eyebrella and it just vanished. I rolled back, and 2 days later I dropped it again while on the boat and it vanished again.

First I thought it was due to the invisible backpack itens problem (another bug), but backpack itens reappear when you drop the backpack and equip it again. I searched allover the boat, and couldn't find the eyebrella.