Shulker box disappear when you are in other dimension

I put my shulker box in end dimension then I go to end city to raid for elytra then I come back and go to home portal then I come back to overworld then I think that I left my shulker box in end let bring it back then I go to end it was not their then I ask to my friends who play with me he say I don't have then I fully search shulker box in end but I not found it please fix the bug it is very hard inside my shulker box was netherite pickaxe that I get very hard now it gone please fix it or it is waste of items of people I don't have screenshot because I not take it but I say that it is real not fake I hope you fix it.