“Darkness” rendering incorrectly when reloading the game.

How to reproduce:

1. (not necessary) Give a night vision effect, it will help you to show the bug more obvious. /effect give @a minecraft:night_vision 999
2. Give a darkness effect. /effect give @a minecraft:darkness 10
3. Exit the game.
4. Reload the game.
5. Waiting until darkness effect ends.

You'll see that the bug happening. The world is flashing. Please watch my attachment and that's a record of this bug.