Problem in the End

I had died in the nether when my mate had grabbed all my stuff and put into shulker boxes and put it into the end spawn in the obsidian box and when I spawned in there it was gone, I’ve never had this issue with chest and/or barrels before so I thought shulkers would be the same I need help please, I was never made aware of any bugs that could affect that, I’ve done it on other worlds and it stays there but today obviously not