Samadhi_Oleks You may have told the game to open in windowed mode at some point. To change it back, open Options > Game Options > Graphics and choose Fullscreen or Windowed Fullscreen.
If this doesn't work, did you tell Steam to launch the game in windowed mode? You'd do it like this (the Steam section of the guide), except you'd add -w instead of -dx11 (for DirectX 11):
DirectX 11 (DX11) for The Sims 4 - A Step-by-Step Guide | EA Forums - 11811172
If you did add the -w command, remove it so the game can switch back to fullscreen when you tell it to do so.
Im very very very appreciate 🙏 Thanks so so so much ❤️
