Refresh rate is only at 60 HZ when using multiple monitors

I have 3 monitors connected to an Nvidia card in my desktop machine. Two of them is 144 HZ and one is 60 HZ. I’m using KDE Plasma 5 + X11 with Nvidia driver. I’ve tried Gnome, Xfce and it seems that they also have this problem.

The issue is, when the 60 HZ monitor is plugged in, only my mouse cursor is running at 144 HZ. Windows on all monitors are running at 60 HZ. I’m sure about that because when I unplug the 60 HZ monitor and move windows they immediately become much more smoother.

I’ve seen some discussion about this, like this one. They mentioned that this can be solved by setting CLUTTER_DEFAULT_FPS and __GL_SYNC_DISPLAY_DEVICE. But it did not work for me after I set them in environment.variables and set configs in nvidia-settings.

My configurations are:

  # hardware configurations
  services.xserver.videoDrivers = [ "nvidia" ];
  services.picom.vSync = true;
  hardware.enableAllFirmware = true;
  hardware.nvidia.nvidiaSettings = true;
  hardware.nvidia.nvidiaPersistenced = true;
  hardware.nvidia.modesetting.enable = true;
  hardware.opengl.enable = true;
  hardware.opengl.driSupport = true;
  hardware.opengl.driSupport32Bit = true;

  # x server configurations
  services.xserver.enable = true;
  services.xserver.layout = "us";
  services.xserver.displayManager.sddm.enable = true;
  services.xserver.desktopManager.plasma5.enable = true;

  # configurations to adjust monitors
  # DP-0 is the monitor that is 60 HZ
  services.xserver.displayManager.setupCommands = ''
      ${pkgs.xorg.xrandr}/bin/xrandr --output $CENTER --primary --output $LEFT --left-of $CENTER --output $RIGHT --right-of $CENTER

Also it seems that Gnome + Wayland and Gnome + default driver works fine. But not for KDE.

Is there anything I did wrong?

Finally solved it using this solution.