Naga

@JomaZ
I had this problem plaguing me for several years but it was fixed for 1.20 just as this ticket states. You might be having a similar but separate issue. Good luck with it!

For me 1.18.1 is actually the first version I have ever consciously noticed the bug in. It's unfortunately now present in many places in my singleplayer world, which I have played in ever since 1.8. For a fixed render distance the chunk borders where it happens will always be the same. Changing the render distance however changes the chunk borders which cause the issue.