The bug
A world can have an entity with the same UUID in each dimension. This causes various issues like MC-151270, MC-153319, MC-184266, or MC-195337.
How to reproduce
Add an entity with UUID
0-0-0-0-2cfcc
in the overworld./execute in minecraft:overworld run forceload add 0 0 /execute in minecraft:overworld run summon minecraft:item_frame 0 0 0 {UUID: [I; 0, 0, 0, 184268], Fixed: true}
Add an entity with UUID
0-0-0-0-2cfcc
in the nether./execute in minecraft:the_nether run forceload add 0 0 /execute in minecraft:the_nether run summon minecraft:item_frame 0 0 0 {UUID: [I; 0, 0, 0, 184268], Fixed: true}
→ ❌
Summoned new Item Frame
Related issues
is duplicated by
relates to
Comments

Can confirm in 21w39a.