Dark in edges of "Old Style Map"

After the Aquatic Update my world went dark about a chunk deep all around the edge of the world. It's most noticeable underground where I am digging my base. Even when I have torches a plenty (IE: An entire chunk littered with torches) or only a few torches. It's still dark. Above ground it's the same thing under trees and any rocky over hangs even in bright of day.

Not game breaking, placing a new torch fixes it temporarily. It reverts back to darkness upon reloading of the game.