I was having spotty internet connection yesterday so I learned that if not connected to the internet when the game loads, the EA app will only recognize the few packs I installed through the app and not those I installed through Origin. This happened even after a repair of my game through the EA app that appeared to run through all the content.
However once I was able to load the game with the internet connected, the game continued to play all my packs just fine when the connection went out during play.
I finally figured out how to use the app in offline mode. Since I logged in to the app online and then switched it to offline mode it had all my packs when the game loaded. Apparently it's just when the EA app opens offline, such as if I try to start the game from the Sims4 icon on my desktop rather than the app while my internet is down, that it doesn't recognize my packs.
My biggest problem is that so many options, like offline mode and repair game, are harder to find than they were on Origin.