How to reproduce, put yourself in a room with 4 walls, one of the walls should be just outside a chunkborder, and the rest of the room inside the chunk.

Important that all walls are inside the chunk except one.

This will trigger some optimization code in minecraft where minecraft realizes that it doesn't need to render what's behind the player since the player isn't looking that way, but it removes the optimization too late and completely ignores FOV settings.

At default FOV there's a small slice of unrendered world until you have turned enough (45 degrees to the normal of the wall at the border). At Quake Pro FOV there's a large part of the screen that's unrendered, and at lowest FOV there's no issue.

As soon as you expose your room to another chunk the issue goes away.

Image explanation:

Image 1: The room
image 2: Image of the issue with default FOV
Image 3: Image of the issue with Quake Pro FOV
Image 4: Issue went away when I punched the block (the block I punched is inside "my" chunk, the block behind is in the next chunk)
Image 5: Issue reappears when I place the block again
Image 6: Just the place where I was punching blocks, so you could see the local chunk coordinates.