crackerjackers Are your Steam and EA accounts currently properly linked? Even if they were before, please check again now. Open any EA website (this one is fine) in a private browser window and try to login with your Steam credentials. If you land in the correct EA account, they're linked; if anything else happens, let me know.
If the account link isn't the problem, please do a clean uninstall of Sims 4 and the EA App, as described in the accepted solution of this thread:
[CURRENT ISSUE] Sims 4 DLC shows as installed, won't load in-game | EA Forums - 11831673
Anchors don't work on this site at the moment, so use ctrl-F to search for revo and jump there.