The game doesn't read the anti-aliasing settings correctly

@GiardiniDiMarzo  Try deleting Options.ini to see whether it helps.

If it doesn't, the relevant Nvidia Control Panel settings are something like this:

Antialiasing - FXAA: On
Antialiasing - Gamma correction: On
Antialiasing - Mode: Override any Application Setting
Antialiasing - Setting: 2x [or higher]

You may need to play with the settings to get exactly what you want, and be sure to apply the settings to TS4_DX9_x64.exe since you're running the DX9 version again.

@GiardiniDiMarzo  TS4_x64.exe now runs the DirectX 11 version of Sims 4, but you'd have to tell the App to run Sims 4 in DX11 mode to use it.  You'd also see DX11 after the version number at the Main Menu, as opposed to DX9 if you haven't switched.  And you should be able to see the executable in the Task Manager too.

@GiardiniDiMarzo  The better option is whichever one gives you the results you want.  In general, I trust the Nvidia setting more than the in-game one, and the results I've heard from other players back that up.  But there are times when the Nvidia setting doesn't apply correctly, for example with certain dual-GPU laptops, and a few players have reported bad results with it over the years.  So try each one and see what you think.

It sometimes helps to set a Max Frame Rate in the Nvidia Control Panel as well, although it in theory shouldn't be necessary if you're enabling vertical sync in either location and only playing in fullscreen mode.