Rodrigo Malca

FPS in 1.16.5: 775
FPS in the latest 1.17 release (1.17.1): 325
Your operating system: Windows 10 x64
Your CPU: Intel(R) Core(TM) i9-9900KF CPU @ 3.60GHz 3.60 GHz
Your Graphics card and driver version, as reported by the game: NVIDIA GeForce RTX 2070 SUPER/PCIe/SSE2 3.2.0 NVIDIA 471.41
Your profiling zip file: 

Same problem here, I can reproduce it by opening a local server and connecting to 127.0.0.1.

^{EDIT: After installing 64-bit Java I see that the tps have normalized and the bug disappears. Before (with 32 bit java) the tps were very low.}