Sims 4 added to child account, but EA app just shows a blank square

I'm trying to get my daughter set up to play Sims 4 but I'm having no end of difficulties. I've done this in the past for my older daughter and everything was pretty straightforward. I set her up Steam and EA accounts, added the game to her Steam library, and everything pretty much just worked. This time around has been completely different. Installing the game through Steam requires me to link her Steam and EA accounts, which it tells me isn't possible as one of the accounts is ineligible. Adding the game to her EA account myself is impossible (as child accounts don't have access to the store and therefore can't claim free games) so I had to contact support to get it added. This is supposedly now done, however the EA app just shows a blank square where the game should be (screenshot attached). It's been like this since yesterday when support added the game. If I install the game through Steam the EA app does show the blank square under "Installed" instead of "My Games", but I still can't do anything with it. I've rebooted, cleaned the EA app's cache and even reinstalled it, all with no effect. It really shouldn't be this complicated! Has anyone else experience this? Can anyone from EA help?