Two ticket numbers for a segment?
 

I have a trip with four segments. There is one ticket number for the entire trip (that is, each of the segments has this ticket number). One segment has this ticket number, plus another ticket number.

Three segements are AA codeshares; the interesting segment has the operating carrier's flight number. Perhaps it's because shortly after purchase, that segment vanished, so the travel agent (AAVacations) had to rebook it. Also, aa.com shows the trip as "on request", while the operating carrier and aavacations show it as "confirmed".

Is this odd or worrisome? I've never seen it before. AAVacations tell me not to worry.

You can have multiple tickets for one reservation. My guess is the system is a bit confused. Call your TA and have them look. They can fix it if needed.

AAVacations is my TA and they say there's no problem, so long as I have at least one ticket per flight segment all is well, but I don't know if I should believe them. A confused system seems potentially dangerous.

Multiple tickets for one trip is understandable. Multiple tickets for one flight segment seems odd to me.