I search via Artist for the band “Opeth” from my library. In the results, under Artists is the band name “Opeth”. I select it and then I see all my Opeth albums. All fine so far. If I click the menu icon on the right of the listed albums for the album “Watershed” and select “Clear and Play”, Volumio adds all the songs from the Opeth album “Watershed” AND the tracks from the album of the same name by K. D. Lang 
Amusing the first time. I then checked my tagging - all seems OK and then I rescanned the library but the problem persists.
So I looked for another album name duplicate in my library. I have “Life” by Simply Red and “Life” by the Cardigans. The same thing happens when I search for the band Simply Red, “Clear and Play” the album “Life” and both albums by the two artists are added to the playlist?
So, I then discovered that if I search by Album for “Watershed” it returns the K.D. Lang album only, however, if I add the album to the playlist, I get the K.D. Lang album and the Opeth album? So it seems the GUI’s SQL requests ALL songs matching the album name field value instead of the specific album returned in the initial search. Perhaps the database treats album name values as unique?
Any ideas if there is something I can do about this?
My current system version is 2.118