Re: DLC not working on steam after linking with origin
@Wrightlesssmalls You should see two Sims 4 entries in your Origin game library, one with a Steam logo and one without. Please try downloading your packs from whichever one you haven't been using.
By the way, is there a reason you want to play through Steam? As you've seen, you'll still need to run Origin or the EA App alongside Steam, and you won't get any extra content, or even better sale prices, from Steam. (The sales might be timed differently, but the discounts are usually equivalent.) I'm happy to try to help with you current setup; I'm just saying it might not be worth the trouble for you when an Origin install should work properly.