This has been happening to me as well.
SIDs/STARs are translated to fixes, and as you pass a fix, it disappears from the flight plan.
Shortly after passing a fix, the departure weather comes up inside my simulator, which is a surefire sign that the flight plan has been resubmitted. Fix by fix, the flight plan shrinks as the flight progresses along.
777/ASN work together beautifully though.