Ok, I have also a problem with my keys:

My tier has a physical copy of the game + 1 additional digitial key.
Furthermore I have selected as an add-on one additional copy of D:OS - so altogether, I should get one physical copy + 2 digital keys on Larian Vault. However, there is only one digital key for my add-on on Larian Vault, but no key for the other digital copy.