While "American Airlines" is a worldwide company, each local employee is acting in their own self interests so they do not violate the law in that country. But to their credit, the first employee they dealt with did try to flag it as a problem and tried to escalate it, but it sounds like OP just wanted to move ahead without the resolution.
From time to time stuff like this happens. If it has this profound of an emotional impact on you, I highly recommend the services of a travel agent. They are getting paid by you to understand what will and wont work at every step of the journey.
Some will throw away one of your names, some will truncate it, some will concat both.
Since these systems talk to other systems my name is often on an unexpected state.
At best this makes accumulating miles really challenging. At worst it got me denied from boarding once.
Airline systems are setup for first name, last name and maybe middle initial. That's how the US works and almost no one else.
Misspelling in title.