Qobuz Grand Selection does not identify that albums are in library. They are missing the "in library" icon and when you click on an album, the "+" indicator is visible even if all versions of the album have already been added to the library.
That is by design. This section doesn’t show content thats in your library it’s a mirror from Qobuz API, it’s just a window into your Qobuz account and not Roon.