I'm having difficulty putting together an itinerary on aa.com - perhaps someone knows a workaround.

Here's the itinerary:
12/22/06 AA 64 JFK-ZRH
12/23/06 LX 3634 ZRH-DUS
12/29/06 AA 83/350 FRA-ORD-LGA

Although I have selected "choose by schedule, 50 flights to display" and "all airlines," aa.com refuses to show the ZRH-DUS flight by LX, but will show LX to BRU (then BRU-LHR then LHR-DUS). I was able to get this itinerary on travelocity, but would prefer to book on aa.com is possible.

LX 3634 is a codeshare with LH, operated by Eurowings, so I'm not sure if that is the issue here.

Looking forward to your advice. Thanks!