Cave Culling Algorithm doesn't work very well, especially in certains situations like the one I'm writing about.

So, in order to reproduce this bug, you have to build a wall all around a chunk, as you can see in the first attachment.

Now, just go near one of the walls and look around. What you'll see are huge black spots, that are chunks not rendered because they're not reached by the algorithm.

You can also make another wall inside, and you'll notice that chunks now are rendered correctly, but as you break one block of the wall the bug reappears.

These walls are built from the floor of a "redstone ready" preset till the "y = 0" of the chunk above. If you break just one block, the bug will disappear.

Of course this is an ideal situation, it happens in way more places other than this heavily-controlled setup, it could happen just making random walls and going near them.

I made also a video, if the screenshots and the description are not enough: https://www.youtube.com/watch?v=m1qeOt5CQgE