blexi3 This usually happens because the player has signed into the wrong EA account, as in, not the one that owns the content. Please do try signing out and restarting your computer though. For more information in English, please see the first post of this thread:
https://answers.ea.com/t5/PC/Sims-4-Packs-missing-from-EA-app/td-p/12225497
Since this forum only supports English at the moment, I'll lock this thread here. Feel free to repost in English, or if you prefer, you can get help in French on Answers HQ:
https://answers.ea.com/t5/Problemes-techniques/bd-p/Les-Sims-4-FR