CatLover-Int It's possible your existing installed Store content is permanently broken, and what you've described is one common way for that to present. Uninstalling the items doesn't remove the broken files, and reinstalling just piles more data on top without repairing anything.
So please try installing one of them into a clean user folder. Remove or rename the entire Sims 3 folder in Documents > Electronic Arts, open the launcher to spawn a new folder, download a fresh copy of one world, install it, load the game to confirm it's there, quit, restart your computer, and load the game again. If the world is still there, install one more and test, then the others one at a time. The launcher doesn't handle large amounts of data well, so it's necessary to do this in steps; if you have other Store content too, install it in small batches, not all at once and not at the same time as a world.
I've deleted the sims 3 folder, downloaded Lunar Lakes and installed it, restarted my laptop and started the game. The world is not in the dropdown menu.
