Originally Posted by
k3bab
After studying the booking realised the flight we picked is 2 hours longer than the other ones on that day. Further investigation uncovered that it was a connection flight but interestingly online booking process showed it as direct (and still does).
If your flight stops somewhere on the way before continuing to your destination (eg SYD-BKK-LHR), it's still a direct flight even though it's not a non-stop flight. All non-stop flights are direct, but not all direct flights are non-stop.
Could this be the explanation for what you saw?