After adding bobby mod, I noticed that when I joined servers or singleplayer worlds, chunks around me wouldn't render until I updated blocks in the chunks or used F3+T. Changing my render distance also makes it go away, but only for a few seconds before it comes back. Using any of the prior methods, the issue always comes back within a few minutes. I double-checked and made sure it was bobby mod, and when I removed it from my fabric mods folder the issue was solved.

Needs more info. What Minecraft version is this? Bobby version? Other mods and their versions?

I also have this same issue on 1.21 fabric with bobby 5.2.3