I used to be able in booking:
DXB (or DOH) - HKG - Chicago/New York/Toronto in V-class fare with 2 stop-overs at Hong Kong (both inbound and outbound).

However, when I was searching for flights recently, the website will not pull any flights and simply showing an error message like no flights are available if I put 2 stop-overs. I did find itinerary with only one-stop over in the inbound (but not outbound).

Moreover, if I try to search DXB - ORD (or other US cities) = YYZ - DXB all options in the return portions involving taking an AA flight to US and connect over there. The non-stop YYZ - HKG flights are showing NA (I search as far out as June 2016, all days were like that). Similar if I searched for DXB - YYZ = ORD (or other US cities) - DXB, all return flights involving a connection in Canada on code share. The nonstop ORD/JFK - HKG all showing NA.

I appreciate if someone can assist:

1. Is it that only 1-stop-over at Hong Kong on the inbound is allowed nowadays?
2. Is it that I can no longer do an open-jaw between US and Canada?

(I am searching for tickets DXB (17 Dec) HKG (20 Dec) ORD = YYZ (28 Dec) HKG (3 Jan).)

Thanks in advance for any advice.

Call CX DXB and ask. Fares change all the time.