I'm trying to book a multi city ticket with 2 'legs' (one of the legs has more than one stop) using AA's international partners for the most part. If I try and book using a multi-city ticket, AA shows me a sign saying 'sorry one of the fares is not available' and urges me to rebook at the screen where I'm supposed to input passenger information.

I can see the legs separately in one way searches, and indeed put holds on them, but those are separate PNRs. I know there are restrictions on multi-city itineraries, but I don't think my legs would fall under those restrictions. IIRC, I did make similar bookings in the past. Also, if the multi-city trip is forbidden, AA has a different error message (this message urges me to rebook).

[ This is an award flight, but I'm not sure that would make any difference]
Questions
1) Is there any way to work around this from the website except to book each leg separately?
2) Otherwise, can I call in and get AA to make the booking manually or even merge the 2 PNRs into one?

Thanks!