@stickysara Try playing 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 hte EA App needs in order to run. Disable the rest as described.
When you reboot, go through the Task Manager's background processes list shutting down anything that doesn't absolutely need to be running, for example GHub might have still been active had you not removed it. If you accidentally kill the wrong process and it doesn't restart on its own, just reboot your computer again.
Please also put the EA App in offline mode for this test as well. If you still get lag, restart your computer, repeat the process with the Task Manager, and this time, put the EA App in offline mode and then take your computer completely offline before pressing Play.
The idea here is to remove everything else that might be interfering with Sims 4, and once the game is running well again, start adding back services until you find out which one is causing the problems.