I had a donkey with a chest full of valuable goods that I had tamed with a saddle on it... I had trapped it so it could not escape... when I rejoined the game my donkey had dissapeared with all of my valuables... Valuables include 6 diamonds, 2 emerals 2 and a half stacks of iron ore 2 water breathing potions, 2 enchanted books (idk what they were), 2 hearts of the sea, 47 gold ingots