Walking through a world on a server, mapping out the area.
i had just turned my render distance up to 32 chunks as well.

these chunks, which i have walked though before we rapidly changing into different biomes and layers. each chunk was exactly the same at any given time.

i had turned the render distance up to 32 chunks, that seemed to cause it
after from science, i determined that it only happens at render distance 32 and it kept happening in the same place

i tried re-logging, that didnt help

entering the "demon chunks" the landscape behaved normally... not corresponding to what was shown (i believe it was a rendering issue)