celipina The problem is that you have two copies of Sims 4 installed, one each from Steam and the EA App. Each one includes the packs you own through that launcher but not the other because those packs are installed into the corresponding version of the base game. The fix is to have only one copy of the game installed, specifically through Steam.
Please uninstall Sims 4 through the EA App, clear the App's cache:
https://help.ea.com/en-us/help/faq/clear-cache-to-fix-problems-with-your-games/
and restart your computer. Then open the EA App game library, click Sims 4 > Manage > Manage add-ons, and install your DLC from there, but NOT a second copy of the base game.
If that doesn't help, please do a clean uninstall and reinstall of Sims 4, and the EA App while you're at it (you don't need to uninstall Steam), as described here:
This seems very logical. The other platform's forum also said "move the EP folder". Both of yours are useful information. I wish I had learned it before I panicked and returned it. :") It will be useful for anyone else who has this problem later. Thanks. <3
