Last column of debug world entities is duplicated

The bug

In the debug world, there are two copies of some entities: birch boat with chest, chicken, drowned, falling sand, guardian, etc. All entities that end up in the last column also appear in the first column of the next row.

How to reproduce

1. Create a new debug world (hold alt while changing “world type”)

2. Fly over by the entities

3. /kill @e[type=chicken]

Expected result

There should only be 2 (one adult, one baby)

Observed result

There are 4, one in the first column and one in the last column