krash1220 To be clear, in Sims 3 camera mode, can you not move the camera with your mouse at all, or do some functions work? As in, right-click to center, hold middle mouse button and move to change the angle, scroll on the scroll wheel to zoom in and out in a straight line rather than the angle changing like with the Sims 4 camera. And does the scroll wheel work outside the game? I just want to make sure none of these work and it's not a mouse problem.
Anyway, please try playing in a clean boot (not a clean Windows install, just a way to disable background apps that might be interfering). Here's how:
https://support.microsoft.com/en-us/topic/how-to-perform-a-clean-boot-in-windows-da2f9573-6eec-00ad-2f8a-a97a1807f3dd
The one service to leave enabled is the EABackgroundService, which the EA App needs in order to run. Disable the rest as described.
When you reboot your computer, go through the Task Manager's background processes list shutting down any service that doesn't absolutely need to be running, for example anything from MSI Afterburner to RGB software might still be enabled. If you accidentally kill a critical process and it doesn't restart on its own, just reboot your computer again.
Don't open anything other than Sims 4 and the EA App while testing, not even a browser window.
If this helps, you can selectively reenable services until you find the culprit, then either leave that disabled or (if it belongs to an app you want to keep using) let me know what it is so we can try to fix the underlying issue.