brxwnchxld Please create a new admin Windows account and try playing there. Make it local, as in, don't link it to your Microsoft account. (Choose "I don't have this person's sign-in information" and then "Add a user without a Microsoft account.") You'll be able to launch Sims 4 in the new account without reinstalling anything, but your saves and other user content won't be available. That's fine for now and can be addressed later if necessary.
If this doesn't help, please try the clean boot again, in the new account, but this time with your computer offline. You can sign into the EA App and put it in offline mode, then disable wifi and/or disconnect the ethernet cable.