I had the same problem with all of the 1.20.5 pre-releases and was hoping it would be fixed by the time the full version came out. Whenever I move, the motion lags every 1.5 seconds - I literally count "one one thousand, two," the motion stops for about a half second, then I jerk ahead to wherever I would be had the motion not lagged. I count another 1.5 seconds, and the motion stops, then jerks again. It happens in every direction whether I'm crouching, sprinting, or just walking.

I don't know if these are relevant or not, but I updated Java yesterday (though I had the same problem on the pre-release versions before that), and I do have an OptiFine version (1.20.4). I had no issues with the potato version but that was the only snapshot I ran before the 1.20.5 pre-releases.