Horizon GPD/Package Adding IMPOSSIBLE (Diamond?)

I’d like to add some GPD file to my profile (eventually upgrading my account to “Diamond” if necessary).
But it seems not properly working.

If I add a GPD file, it regularly appears in the “Contents” TAB listed together with the others.
Nevertheless it doesn’t appears in the Achievement list, so no achievement is unlockable.

Am I doing anything wrong?

Yeah you require diamond. Just injecting the .gpd into the profile will not make them appear on your game list. I believe it has something to do with the account file, that needs updating to display said game…