Rosetta version isn’t more specific because it doesn’t need to be. From Rosetta’s perspective both are okay and on the page there are various implementations - with zero-padding in numbers and without.
However since here tests require more specific result, it will be good to either clarify description, how such case should be handled, or change test to accept both.
It still seems odd to me to have such vagueness in a challenge description, but if the tests can handle both implementations, then that is at least a good improvement and should suffice.