Shucker box full of items disappeared

I was playing in my Realm on Minecraft Bedrock PE, and i had 7 shulker boxes. i went on a mining trip and found 8 diamonds, a bunch of gold and a bunch of iron, i also had like 9 or 10 night vision potions as well as 2 empty glass bottles. i arrived back to my base and placed one of the shulker boxes, which contained the iron, gold, diamonds, potions, and glass bottles. i took out the iron and gold to smelt it, then when i was sorting my items after smelting them i realized that the ahíleme box i had places was now missing. i still had the other 6 in my inventory, but the one that i placed with all of my items in it was no gone. it disappeared. i looked in every single one of my chests and even looked in my remaining shulker boxes to see if maybe i had accidentally placed the one in question in a chest. i did not, it was just gone. i am now very upset because although 8 diamonds isn't very many, i had none before this so i was glad to have some to repair tools and things. but now all of my stuff is gone.