When vsync is enabled and you set fps limit to more than 60, mouse movement is jittery.
However with vsync on,and fps limit to 60 the mouse doesn't jitter anymore.
How to reproduce : Settings - video settings - set vsync to on - and set max fps to unlimited (or more than 60)
It happens to me too, when I play the game but my v-sync is active, with f3 open it says 60 fps, but it looks like it is going on 30fps... and it isn't my monitor issue because it is a 60hz so it can play games at 60 fps completely fine, even with gta or farcry, terraria or any other game it is always 60 fps stable, my pc is also a i7-8gen, gtx1060 and 16gb of ram, I even have an SSD...
So please don't tell me that to play minecraft I need a i9 and an rtx2080... this is a minecraft issue, please fix it, it started to happen since 1.13 came out, and it is still present in 1.14.4, I don't want to deactivate my v-sync to play fluid, because I hate to see random lines on my monitor... so please Mojang fix this!
I can confirm this bug!
Thanks!