Shulker boxes cause crashes and on some occasions they get completely erased from the world along with the items in it.

After a long day of grinding in the nether with my friend, we stored up tons of items into shulker boxes. When we got back to our base, we placed down the shulker boxes to unload our items. When I opened the shulker boxes my game crashed. When we got back into the world but our shulker boxes were gone, as well as one of our ender chests. Ever since the 1.16 release we had crashes due to opening shulker boxes but this was our first encounter with disappearing shulker boxes.