The frame rate is not as configured as expected

I’m working on a frame synchronization mini-game, and now I’m implementing the function of reconnecting the disconnection. My train of thought is: the normal frame rate is 50 frames; The frame rate was set to 200 frames per second and the sprite was quadrupled, but I found that there was no guarantee that it would be 200 frames per second when it was running, and some frames were too different from what I expected, resulting in a noticeable out-of-sync between different clients. Am I developing the disconnection reconnection function with the wrong idea? If you don’t have a problem with your thinking, how do you deal with the problem that the frame rate and time per frame do not meet expectations?