Display Type in Options: Fullscreen, Windowed, Windowed Fullscreen
If that for some reason fixes it, I'd try using "Windowed Fullscreen" that way you wont even notice a difference.
Not sure what else to suggest. Possibly if the mouse is a performance mouse and has it's own software (like Razer or Logitec), try disabling the software?
Make sure drivers are up to date on the computer I suppose... try a different mouse if you have one around.
You could try renaming:
C:\Users\<USER>\Documents\Electronic Arts\The Sims 4
to "The Sims 4 BACKUP" and relaunch the game. That should put a lot of things back to default if a setting got changed or something.... If you have saves/mods whatever else in the old folder you can copy those back or rename the entire folder back if it makes it worse for some reason.
