When I opened my 1.17 world in 1.18, I spawned into old chunks and there was next to no lag. But, when I tried to enter new chunks the framerate dropped massively and no amount of setting changes could fix it. Attached is an image of me in newly generated chunks.
MC-244085
Generating new chunks creates lag
Resolved
Invalid
0
Just looking at your F3 screen, your memory is almost completely used up, so assigning more could probably help. If the issue persists, please attach a profiling report by pressing
F3+L.