@ElineEL Okay, please undo that change, since it's not helping. There are two troubleshooting steps you can try next; pick whichever one you want first, then move on to the other if it doesn't work. One is to try to play in a new admin Windows account. Make it local, as in, don't link it to your Microsoft account or any email address. You'll be able to launch Sims 4 without reinstalling anything, but your saves and other user data won't be available.
The other step is to play in a clean boot:
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 neither works, try a clean boot, in the new Windows account, while your computer is offline. You can sign into the EA App and put it in offline mode, then disable wifi and/or disconnect the ethernet cable before pressing Play.