I've started having some strange issues with pop-in while using bobby, where chunks that I've previously loaded will unload and reload multiple times while I'm looking at them. This just started yesterday, as I've played on this exact world without this issue just a few days ago.
Specs:
RTX 3080
Ryzen 7 3800XT
16gb 3600mhz DDR4 RAM

Current modlist:
Another Furniture
Balm
Bobby
Cardinal Components API
Chalk
Chalk Colorful Addon
Cloth Config
Coroutil
Create
Create Utilities
Eureka
Fabric API
Fabric Language Kotlin
Create Storage
Immersive Aircraft
Indium
Just Enough Items
Lithostiched
Mod Menu
Sodium
Tectonic
Traveler's Backpack
Valkyrien Skies
WATUT
Waystones
Yet Another Config Lib
Zoomify

Game and all mods are on 1.20.1. I've also made a small youtube video showing the issue. You can see it occurring around the 20 second mark. This occurs both in the aircraft and on foot.
https://youtu.be/ZzgwXriUfeU

Please list the versions of your mods.
Please also try to reproduce it in a fresh world / a copy of your world with as many mods removed as possible.
Ordinarily Bobby will replace chunks immediately and seamlessly when they're unloaded by the server. To do that, it must prevent the renderer (in your case mainly Sodium) from unloading the chunk. So it might break with Sodium versions it has not been built for.
Or there might be a third-party mod which makes changes to the way chunk scheduling works, which could similarly cause the chunks to be unloaded (before being reloaded).