It is entirely CONSTITUTIONAL, therefore, for CONGRESS to define such terms. Courts, for many years, had to resort to Common Law for a definition of citizenship, itself.
Then, legislation was passed by Congress as to what requirements had to be met, to be a Citizen at Birth.
Hamilton shot another founder in a dual. Adams and Jefferson hated each other.
Our Founders, more than likely, disagreed on many citizenship issues.
This is WHY the definition of citizenship was left to Congress.
Which provision of the Constitution gives Congress the power to do this?
The only power I see delegated to Congress involving citizenship issues is the power "To establish an uniform Rule of Naturalization".
So, any person who is a citizen at birth due only to a law passed by Congress, must therefore be considered to be a naturalized citizen.
The 14th amendment defines persons born in the US to be citizens, but does not define them as "natural born" citizens.