Try changing your numbering system to 2-digits (00 - 99) as a prefix in the title field of your ID3 tag.
(Maybe also use these 2-digit numbers in the track field of your ID3 tag.)
Change this: 1-1, 1-2, 2-1, 2-2, 2-3, 2-4, 3-1, 3-2
To this: 11, 12, 21, 22, 23, 24, 31, 32 etc