(Note: this is not my video, the person who's video it is wanted someone else to open the issue)
If the player is outside of water and there are entities in the water, the entities disappear at certain angles.

Video:
https://cdn.discordapp.com/attachments/602805020861267968/766655976543223828/HIiPRNcDxZ.mp4
Imgur link (so you don't have to download):
https://imgur.com/pEjte0c

Note 2: spacey claims to have the same problem in the discord. I'll send over the video once I get it

A pretty good image by spacey. Probably pretty useful considering it's not the entity itself getting culled but the actual texture
A video, also by spacey.
https://youtu.be/ssvLvLENB0Y

We've had conflicting reports in the Discord about this bug report. One user is saying that they can reproduce this issue in vanilla (without Sodium). Another user is saying this is probably caused by another mod that spacey is using.

Regardless, I feel comfortable saying this is not caused by Sodium. I'm going to mark this as a feature request for now. Can you provide a full list of mods (with versions) that spacey is using as well as an F3 screenshot?

EDIT: This has been confirmed to be a vanilla bug. No need to send any mod information.

I'm leaving this open as a feature request, it's ultimately up to Jelly if this is within the scope of Sodium to fix.

Attaching clearer videos by fancyflacko for clarity
With Sodium
Without Sodium