Minecraft Java Edition 1.20.1 extremely low fps (High-end PC) (Windows 10)

When playing the new 1.20.1 update on single player worlds and multiplayer servers my FPS drops significantly.

When entering a world I will begin at 144 FPS (what I have it capped to), but it will drop steadily as chunks load. Within about 5-10 seconds, my FPS will fluctuate between 27-144, but when I move around (even slightly) my FPS will drop under 50.

I played around with settings like V-Sync, Render/Simulation Distance, Mipmap levels, Chunk Builder, Entity Distance, and FoV. I also allocated 8Gb of RAM to my 1.20.1 installation, and set Minecraft's priority to "Realtime" in Task Manager. I have also set OpenGL to my graphics card to ensure the application isn't accidentally using my CPU's integrated graphics. None of these things had any effect on the issue.

I also monitor my GPU and CPU usage and temperatures while playing, and they are lower than expected.

I do not have similar issues on earlier versions of Minecraft Java edition. I also experience the same FPS issues when using the Optifine client for 1.20.1.