While working on a Minecraft project I noticed that if a player is in a Superflat world, if they are above and behind a wall (in which the other side of the wall is clearly visible), and if looking just slightly downward, the chunks on the other side of the wall will not render. I have 4 walls which converge at the coordinates of 0 4 0. The height of each wall is 16 blocks and they extend outward 256 blocks. I do not know of this also happens in worlds other than Superflat. Here is a video of it https://youtu.be/ZTqKtoKsLJM