FPS does not change
No FPS increases regardless of graphics settings 59-60, no more or less
The FPS limit is 60 FPS or less. This is a normal situation. It's the ideal for consoles and the norm for PCs. If you're happy with the picture quality and performance, don't sweat it and just play for fun. If you really need to see 73 fps or 120 fps, and the game is not comfortable (although 60 fps is great), then search the forums, to remove the limitation of 60 fps. But note that after removing the limit you will increase the load on the system, cooling fans will howl, and the game may not be so comfortable. Generally speaking, for usual games (even shooters) a stable 60 fps without slippage is great for comfortable gaming. Maximum FPS is only important for online battles in high-intensity online shooters, which are more related to eSports than to entertainment for the evening or two.
In the Nvidia settings, it might be locked. Manage 3D Settings - Software Settings
All limits are disabled everywhere. Same situation in Assassins Creed Origins.In Assassins Creed Odyssey FPS 98-105