Steps to reproduce:

1. Use the seed: 4015 to create a Normal type world(Before 24w40a) or use the seed: 8462 or 20337 to create a Large Biomes type world(24w40a)

Observed result:
The colormap of the world loading screen is black until the percentage reaches 100％.

Expected result:
The colormap of the world loading screen fills out properly in different stages.

Notes:
This happens since 1.20.5. In 1.18-1.20.4, it also is black until 20%+.