Origin is being replaced so you can still play all of your games through it. There's no need to repurchase everything through Steam, just keep playing through Origin.
I would make sure every scrap of Sims is removed from your computer, then reinstall through Origin again.
I tried to do that today, but in Origin it just kept trying to log into my steam to install it. Then I got it to where there were no sims files on my PC. While logging out of Steam. Then it just said Details, and I couldn't install the base game at all. Unless I click on a pack, and then it tries to download the base game through Steam. Like would uninstalling Steam even work to fix it, do you know?
Like I use Steam for other games, but after seeing how wonky it is, I'd rather just keep Origin only for my sims games atm.
@Thornwood-Hollow When you buy the Sims 4 base game on Steam, it supercedes the copy in Origin, and from then on Origin will direct you to Steam to install the game. I take it this Steam account is still linked to this Origin account? If not, that would explain why Steam isn't picking up your Origin content.
Uninstalling and reinstalling Steam might help with the issue, that is if you want to keep playing through Steam. While you're at it, clear Origin's cache and uninstall it "the hard way."
https://help.ea.com/en-us/help/faq/clear-cache-to-fix-problems-with-your-games/
https://help.ea.com/en-us/help/origin/origin/manually-uninstalling-origin/
Restart your computer before installing both Steam and Origin. Once they're installed, download the Sims 4 base game from Steam, then see whether you can install your packs from either Steam or Origin.
@puzzlezaddict I have steam linked to Origin. But I refunded the Steam copy due to this all. Meaning I only own origin stuff. Preferably I'd only use Origin anyhow. But it won't let me play without having both Steam and Origin running. It also won't list my dlc on Steam, just Origin, and only lets me download the base game through Steam. Even though I no longer technically own it on steam.
@Thornwood-Hollow Then try clearing Origin's cache, as described in the link above. (Restart your computer afterwards.) If that doesn't help, you'll need to contact EA customer support and ask for help.
