Same issue here too; I have the DvD stand alone original of Red Alert 3, and although the game appears in my EA App library, having been added a decade or more ago, I get the error message saying I don't own it when I try and reinstall.
Entering the DvD key again gives a window with multiple boxes of RA3 that all I can do is click on them to get a green tick mark, and then can't do anything else, even scroll the window up and down to look for an accept box.
EDIT: I just tried entering the key via the webpage version of my EA account, and it offers those selections too, however although you can get past it there, it just says the key is (unsurprisingly) already activated on my account, so no got there either.
I'm currently trying to get Tech Support to understand that yes I should be able to download it, even if multiplayer has been disabled, no I can't Repair a game I can't install, no I've flushed the cache countless times... Maybe they just want to annoy us to the point we purchase the Remastered collection...
