Gravity blocks can be duplicated using derailed minecarts and chunk reloading

Steps to reproduce:

1. Import and open the attached world: Gravity Block Dupe.mcworld
2. Destroy any dragon eggs next to the derailed minecart
3. Either go through the nether portal to the Nether and back to the Overworld, or exit and re-enter the world

Observed result:
The dragon egg (gravity block) is duplicated.

Expected result:
The dragon egg (gravity block) is not duplicated.