How do i get rid of this/ fix dh and alex caves

https://preview.redd.it/tkdvng49h7dg1.png?width=1919&format=png&auto=webp&s=54048f5ff6ce007532b0033970ac7801d0457b02

So, the game told me to fix some alex caves configs and i turned off the biome lighting one cause that was supposed to fix distant horizons but now there this thing, and im not entirely sure what im supposed to do about it. if anyone can help that would be super!