Sometimes north-south chunk borders are visible in water.

Has anything with rendering changed since the 1.20 snapshots?

Also I want to make note of the fact that it doesn't happen all of the time, it's only like maybe once or twice a day when I'm playing Minecraft for probably 8 hours a day (and it doesn't last long either, usually only a minute or so and it eventually fixes itself; I don't have to reload or F3+A or anything like that)

Also, I noticed that this seems to be tied to MC-261495. Like once the chunks render, this usually happens. It's like the game doesn't realise those chunks are adjacent or something. Sometimes it happens without MC-261495, but they seem to be related somehow. I have also only experienced this while travelling east or west, so that supports my theory.