Improve Query

Source/DataLayer/QueryObjects/LibraryBookQueries.cs

@@ -59,6 +59,15 @@ namespace DataLayer
 #nullable disable
 
         public static IEnumerable<LibraryBook> FindChildren(this IEnumerable<LibraryBook> bookList, LibraryBook parent)
-            => bookList.Where(lb => lb.Book.SeriesLink?.Any(s => s.Series.AudibleSeriesId == parent.Book.AudibleProductId) == true).ToList();
+            => bookList
+            .Where(
+                lb => 
+                lb.Book.IsEpisodeChild() && 
+                lb.Book.SeriesLink?
+                    .Any(
+                        s => 
+                        s.Series.AudibleSeriesId == parent.Book.AudibleProductId
+                        ) == true
+                    ).ToList();
     }
 }