"You don't own this game" despite just redeeming the key.

I have previously played Mirror's Edge via EA Play on my PC and wanted to play again without a subscription. The EA app had no option to purchase the game so I turned to CD Keys. I was able to redeem the code but the EA app is telling me I don't own the game. I have tried reloading the page in the EA app, logging out & in, flushing the app cache and uninstalling then reinstalling the EA app, all to no avail. 

What do I need to do to play this game? Thanks :)