In Minecraft 1.17, I noticed my fps was limited to 60, I checked my settings, VSync was off, and fps limit was set to unlimited, and in Nvidia control panel VSync was set to use application preference, I also have tried force VSync off. Using these same settings in 1.16, worked fine, this issue also occurs in the 1.18 Experimental Snapshot.

I know this is limiting it to VSync, as when I overclocked my monitor to 75hz, the fps limit was then at 75fps. This is an issue as the game feels very choppy, and the fps is constantly dropping.

I have seen many other people have this issue, and ask on forums, and everyone says turn off VSync, change fps limit, and change the settings in things such as Nvidia control panel, I have done all of these, and still doesn't work.

I have also found my old pc doesn't have this issue, it uses integrated graphics on a AMD a8 5550m. However, I cant use it for 1.17 as its unplayable due to it not being very powerful.

It seems this issue effects only Nvidia cards, as everyone reporting this issue on forums say they are using an Nvidia graphics card.

I am assuming this has to do with the update to java 16, as all of the other Minecraft versions are fine on java 8, as soon as you update to java 16 however, this issue arises. 

I forgot to add, when using Optifine / Lunar Client, this issue does not occur.

If you try to duplicate this, possibly try to get someone who has a Nvidia Geforce GTX graphics card to try it, as other reports I looked at that you say you are unable to duplicate the issue, in the images, they have a Nvidia Geforce GTX graphics card.