Snow blocks randomly appeared in a marketplace world

Partner Rank: 3

Verification builds: 1.20.81, 1.21.0, 1.21.30.21
Regression builds: 1.19.83

Summary: In the existing map Nether Monster Hunter, some chunks are incorrectly loading with various snow layers strewn about the ground. This does not happen when loading the world in 1.19 or earlier, only in 1.20. No changes to the world have been made.

Impact: Corruption leading to the world not loading as designed. It's unknown whether this affects other maps currently on the store.

Repro Steps:

1. Download and open "Nether Monster Hunter" from the marketplace
2. Walk forward a bit and look to the left

Expected Results: Part of the build is visible, a path going through a sugar cane field.
Observed Results: Most of that section is covered in snow layers.

Screenshots/Videos attached: Yes