If you place a block on the obsidian spawning platform in the end it is completely deleted once you leave the end. I had a shulker box placed there, and upon going home for supplies and returning it deleted hundreds of hours of my work from a single glitch.
Linked issues
Comments 4
would this duplicate MC-902?
I believe this is intentional as you want some temporary safety time when going through a portal (but also quite useful for some traps that I've made), however, the items should at least drop when coming through the portal.