Various chunks randomly duplicate and randomize in a set space, doesn't impede gameplay, but is an inconvenience

In a certain location in the world, every chunk will randomize whenever the player moves, assumedly one of the chunks in this area, and every chunk will be duplicates of one single chunk. The actual terrain is still traversable, and other players will still appear. Mobs however, will be obscured by the false terrain and will also be very distorted and enlarged and mixed with the false terrain.