Summary:
When looking straight at a cloud at the edge of your render distance, the cloud is not visible, but when turning your head away, the cloud is visible.

Steps to Reproduce:

1. Create a new world
2. Fly up to Y=192
3. Fly away from a cloud until it is covered by the fog
4. Look straight at the cloud and then turn your head away

Observed Results:
The cloud becomes visible when turning your head away.

Expected Results:
The cloud should not become visible when turning your head away.

Video:
Minecraft 2021-10-17 10-32-26-1.mp4