@Caramel_garnish hi there. Is the game asking you to accept the terms and conditions again when starting the game as well? I've seen this happen to a few players recently.
Can you check your account is linked, here are the steps:
https://help.ea.com/en/help/account/link-your-console-accounts/#how-to
You can also to go to profile.ea.com and see if you have the option to accept the terms and conditions there. Also try resetting your password. I've seen that advice from EA when this happens.
It can happen when an Xbox setting is changed or if there's an accidental switch to a new profile. I've done that myself. I've also seen it happen when most save slots are filled. If you go to Sims 4>Manage Game and Add-ons>Saved Data by selecting Sims 4 on your console home screen with the menu button (3 lines), you should see 2 sets of data. What's the file size next to your gamertag/username?
Can you also make sure that your game and console are updated, steps included here:
https://answers.ea.com/t5/Consoles/READ-FIRST-Console-Troubleshooting-Guide-and-Known-Issues-Patch/m-p/12363039#M19682