Not all Albums shown. Tagged classical music

[AmBaKlaRo]

Most conflicts in the log look like this

Warning: conflicting ALBUMARTIST values ignored for album Mozart: "Porgi, amor" (Die Hochzeit des Figaro)
first conflicting value: Schwarzkopf, Elisabeth
first conflicting item: Porgi, amor
second conflicting value: Callas, Maria
second conflicting item: Porgi, amor (Die Hochzeit des Figaro)
Warning: conflicting ALBUMARTIST values ignored for album Mozart: "Voi che sapete" (Figaros Hochzeit)
first conflicting value: Schwarzkopf, Elisabeth
first conflicting item: Voi che sapete
second conflicting value: Patti, Adelina (1843-1919)
second conflicting item: Voi che sapete
Warning: conflicting ALBUMARTIST values ignored for album Mozart: "Ach ich fühl's" (Zauberflöte)
first conflicting value: Destinn, Emmy (1878 - 1930)
first conflicting item: Ach ich fühl's
second conflicting value: Schwarzkopf, Elisabeth
second conflicting item: Ach, ich fühl's (gesungen in Englisch)
Warning: conflicting ALBUMARTIST values ignored for album Mozart: Rondo für Violine und Orchester C-Dur KV 373
first conflicting value: Oistrakh, David (Violine u. Dir.) - Berliner Philharmoniker
first conflicting item: Rondo KV 373
second conflicting value: Oistrakh, David - Berliner Philharmoniker
second conflicting item: Rondo für Violine und Orchester C-Dur KV 373

Most other conflicts like this

Warning: disc number 2 ignored because no ALBUM tag in file Chopin/Nocturnes/Nocturnes_Biret/Nocturne_Nr_20_cismoll_op_posth_72_Nr_2.mp3
Warning: disc number 2 ignored because no ALBUM tag in file Chopin/Nocturnes/Nocturnes_Biret/Nocturne_Nr_15_fmoll_op_55_Nr_1.mp3
Warning: disc number 2 ignored because no ALBUM tag in file Chopin/Nocturnes/Nocturnes_Biret/Nocturne_Nr_16_EsDur_op_55_Nr_2.mp3
Warning: disc number 2 ignored because no ALBUM tag in file Mendelssohn/Lieder_DFD/Erster_Verlust_Op_99_Nr1.mp3
Warning: disc number 2 ignored because no ALBUM tag in file Mendelssohn/Lieder_DFD/Fruehlingslied_Op_34_Nr3.mp3
Warning: disc number 2 ignored because no ALBUM tag in file Mendelssohn/Lieder_DFD/Pagenlied_oO.mp3
Warning: disc number 2 ignored because no ALBUM tag in file Mendelssohn/Lieder_DFD/Nachtlied_Op_71_Nr6.mp3

Attached are screenshots of the composer Sarasate. In Windows Explorer - look for the albums "Zigeunerweisen" - once in the subfolder and five times as a single track file.
In HifiCast under Android Player, however, Minimserver only maps 2 versions.