I have seen this mentioned several times.
But I don’t think it has anything to do with Qobuz.
If I had a Tidal album added to my library, and had also bought it (CD RIP or download), both would appear in my library. Most of the time as versions, sometimes they were not recognized as the same album and I had to do that (4 clicks).
From what I read here, it works the same if you have bought it from Quobuz. Right?
I think that is correct and consistent behavior. It doesn’t matter if you bought it from Quobuz, a download and a streamed version both exist.