Possibly a poorly trained agent. There is a known AS system bug/feature previously described in this thread. AS agents will not be able to find CX flights departing shortly after midnight with a default search. You need to ask the agent to make sure to enter a search time of 1AM when searching for these flights or they will not show up. Some well trained agents are aware of this but unless they are familiar with the CX flight schedules from your departure city and know the flight they are looking for that does not show up on their screen departs close to midnight they may not even realize that they need to do it so they will simply tell you nothing is available. So, you have to take the responsibility to let them know to make sure it happens because they either may not know or may not realize they need to enter 1AM for the search time for these flights.