World chunks sometimes stop loading in or load in very slow.

Summary:
I went into a single player world and turned my render distance to 32 and then I flew through the world and I eventually found some chunks not loading in fast enough

What I expected to happen was...:
The chunks to load in smoothly.

What actually happened was...:
The chunk stopped loading in and I had a hard time continuing on farther in the world.

Steps to Reproduce:
1. Open Minecraft
2. Create a new world (Recommend creative to make this bug happen)
3. Turn your render distance to 32
4. Fly around until you find a chunk not loading in.