Summary:

The world icon is not being saved correctly. If you look into the distance (not the chunk loading zone), the entire area there will be white.

Steps to Reproduce:

1. Enter the world.
2. Look horizontally.
3. Keep the world like this.
4. Exit the world.

Observed Results:

Non-submerged areas (far away) will be white.

Expected Results:

The icon is saved normally.

Video:

Minecraft 2021-02-12 09-23-38.mp4

Image:

Note:

Works also in clear weather, but it is seen better at night or in the rain)