To replicate this issue launch minecraft twice and join the same world with both launched games, after that you rejoin with the first launched game and the world will be corrupted.
MC-176093
corrupted chunks
Resolved
Invalid
0
Wow. I can absolutely confirm this. All the chucks were rearranged once I rejoined the world. I got to looking and found it was only the initial spawn area that was corrupted. Once I loaded in new chucks further out it was fine.