The bug

Walls don't update / change their up: true tag on more than 512 wall height

To reproduce

1. Load the custom world in the attachments
2. Create a tall pilar of water with the command /fill ~ ~ ~ ~ ~514 ~2 stone_brick_wall
   →  The lowest 3 walls in the middle row aren't updated, still have the up: true tag
3. Update the lowest middle not updated wall
4. Go to the tallest wall /tp @p ~ ~514 ~
5. Place a wall next to, or on top of the top middle wall
6. Go down /tp @p ~ ~-514 ~
   →  The lowest 3 walls in the middle row aren't updated, don't have the up: true tag