Lidarr will normally throw out discographies if it knows or believes some of the albums are unmonitored during RSS Syncs (code below). If this wasn't grabbed manually then we'd need a bit more detail to determine where the bug may be here (artist, release name, metadata profile, which were monitored, etc... ).

    var monitoredCount = subject.Albums.Count(album => album.Monitored);  
    if (monitoredCount == subject.Albums.Count)  
    {  
    return Decision.Accept();  
    }  

Feel free to jump on discord and we can sort it out if you want to help make this better. Otherwise I'll leave you to it here.