“First and last name reversed on airline ticket — will this be an issue?

Hi everyone! I’d really appreciate some advice 🙏

I booked an international flight with Japan Airlines (São Paulo → Dallas → Tokyo), but my first and last names seem to be reversed in the booking.

On my passport: Last name: DE JESUS DOS SANTOS First name: MARIANNE

On my ticket: MARIANNE / DE JESUS DOS SANTOS

So all the names are correct, just in the wrong order.

The ticket is issued by Japan Airlines, but the first flight is operated by American Airlines. When I try to enter my passport details on the American Airlines website, it gives an error because of this mismatch.

I’ve read that name changes are not allowed, and now I’m worried 😅

Has anyone traveled with a similar issue (names reversed)? Did you fix it beforehand or just sort it out at the airport?

My flight is in November, so I still have time to fix it if needed.

Thanks in advance!