This isn't a "bug", but how sorting works for most applications.
A dictionary sort orders "1, 10, 2, 20, 3, 4, 5, 6, 7, 8, 9"
A numerical sort orders "1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 20"
When writing an application, the dev has to decide which sorting function to use. File Explorer defaults to numerical sort order, so you're saying you would prefer NTLite to use the same method?