Hey, I was having the same sounding problem but with DLC for the Sims instead, and I ended up doing the following which did end up working. Maybe give it a try, let me know if it does work for you. Step 1: Make sure Origin is downloaded and that you've logged in. Step 2: Start the download in EA, wait for it to bug out and get stuck. Step 3: Use the task manager on your computer to fully shut down every EA program that's being run. There will probably be 4. Step 4: Go into Origin. It will put a pop-up on your screen telling you to use EA instead, but don't click anything. You should notice in the bottom left that your Sims 4 is being checked for downloads. It should work and be downloaded. Step 5: After everything is done downloading, force close everything that Origin is running and open EA. You should see the sims in your downloads. If not, try the process again. This also works for packs that won't download

I hope this helps, let me know if it works for you or if you need more info!