RhysReading I apologize for the late reply. If you're running the game in DirectX 9 mode, please try DX11 mode instead. You can see the mode in the lower-left corner of the Main Menu, to the right of the version number. Here's how to force DX11 mode:
DirectX 11 (DX11) for The Sims 4 - A Step-by-Step Guide | EA Forums - 11811172
If that doesn't help, 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.