You’re only going to notice if the thing playing goes up to 165fps. If you’re, say, watching a movie or video you won’t notice anything because there’s nothing to notice.

Play a game that you can get really high FPS in (maybe Half Life 1 which a modern machine should have no trouble getting 300+). Limit it to 60. Check it out. Then go up to 144. Then 165.

Also if you have an nVidia GPU, it may not be setting the refresh rate properly. I constantly have this issue with driver updates resetting it back to 30hz on my machine. You gotta go into the Nvidia control panel, find the display settings and scroll down somewhere toward the bottom is a refresh rate setting. Change that to the highest your display can use.