1.14pre1 After leaving the nether my world gets covered in random "dark chunks"

After exiting the nether I and checking my farmland, I started to notice a few chunks have incredibly dark shadows scattered randomly around the world, but figured placing a light source and removing it would solve the problem and this would be a minor nuisance but not quite, it did seem to brighten the area to a small extent, but still not enough where I could plant all my crops back without leaving lanterns around, let alone match the rest of the area in daylight, especially with my brightness set to moody.

I have no clue how to replicate this bug unfortunately... but I do know using "erase cached data" in the optimize world options seems to fix it if anyone else encounters this problem.