@zavocado Does it help to play in windowed mode? You can switch in the graphics settings menu. If you can't access that, edit Options.ini, in Documents > Electronic Arts > The Sims 4 to set fullscreen to 0 (zero).
If that doesn't make a difference, please restart your computer before playing and don't open anything aside from Sims 4 and the EA App. Additionally, check the Task Manager, including its background processes list, for any apps that come with overlays: Steam, Discord, etc. If you see any, kill them before launching Sims 4.
If that doesn't help either, please run a dxdiag and attach it to a post.
https://help.ea.com/en-us/help/pc/how-to-gather-dxdiag-information/