Strange pieces of chunks loaded with buffet mode

I found a minor but a bit disappointing bug. The image below shows how some strange pieces of random chunks appear in a world created with the new buffet world mode. This happened when i travelled 3000 blocks away from my spawn (if this information helps). These random chunks are limited and they aren't repeated around the world. Tell me if you need the seed to investigate this small issue.

Thanks, M3T3R3D.