nez0819 Please force the game to open in windowed mode. Go into Documents > Electronic Arts > The Sims 4, open Options.ini, search for fullscreen , and set it to 0 (zero). If this works, you can switch back to fullscreen at the Main Menu, but make sure to also set the in-game resolution to match your monitor.
If this doesn't help, disable any apps you have that come with overlays: Steam, Discord, etc. Disable the EA App in-game overlay as well, under Settings > Application.
If this doesn't help either, please provide a dxdiag. Click Windows key-R, enter dxdiag in the run box, wait for the scan to finish, click "Save all information," and save the file to your desktop. From there, you can attach it to a reply using the paper clip (Attachment) icon included with the other formatting buttons.