I don’t think I confuse the issue. The name of the country is Republic of Macedonia. In short, it’s also known as Macedonia. The republic of Macedonia is recognised by most countries of the world.
The ethnic identity of Slavic people living in Republic of Macedonia and other countries of the world is Macedonian.
Macedonian can also be a national of Republic of Macedonia of any ethnicity – Gypsy, Albanian, Greek, Serb, Bulgarian.

It does not matter how ancestors of modern people identified themselves in the past. Many had several ethnic identities in the last 1,000 years. Germans don’t insist for Austrians to be labeled as Germans. As far as I know Austrians identified themselves Germans in the past.  Certain Czechs were known as Bohemians in the past. Bohemian is a Celtic rather than Slavic term. Bulgarians bear ethnic term applied to Turkic speaking Bulgars originally.  I can find many such examples. What matters is how people of Macedonian identify themselves today. If they consider themselves Macedonians , then they are Macedonians even if their ancestors were known by other ethnic names in the past.