Came across this thread and wish to report an annoying issue.

I was trying to book JL712 (SIN-NRT) to connect to JL4 (NRT-JFK). It’s a redemption booking using AM. But CX website keeps saying it’s an invalid itinerary even though there’s 2:25 hours layover which is more than sufficient for MCT, and BA.com allows this itinerary. Instead the website suggested longer layovers at NRT, even a HND-NRT transfer. Likewise a similar HND transfer seems valid too.

In the end I called AM and managed to book it by the phone without issues.

Would anyone know what exactly causes the itinerary to be “invalid” on the CX website?