Mesa biomes sometimes have their clay layering changed in random parts of the biome.
What should happen: When exploring a mesa biome, clay layering should remain the same in all parts of the mesa biome.
What happened instead: In some parts of the mesa biome, you'll notice that the clay layering abruptly stops and a new set of clay layering begins.
Reproducing this bug:
1. Create a new world
2. Find and explore a mesa biome.
3. Pay attention to the clay in mesa plateaus, you'll notice the clay layering will change abruptly
->If that doesn't work, try recreating the world
4. Recreate the same world, but approach the mesa biome from a different direction
5. The clay banding changes in different places of the mesa biome.
->If that doesn't work still, try exploring multiple mesa biomes. Clay generation will change eventually.
->If that still doesn't work, try changing the video settings
6. Change the video settings so that the game lags a bit or vise versa.
7. Recreate the world and explore the mesa biome.
The screenshot below uses the seed 35267400 and the mesa biome is at ~x+1500 z-120