Guild Wars 2

I am in Dragon’s Stand and have waited patiently twice to start the Northern Assault event. On both occasions, the dragon knocks everyone down (I think this is supposed to happen), it then goes to a cut scene, boots me from the map I was on, and sends me dead to a point near the entrance of the map in base Pact Base camp. I have done this while in a party and also while not in a party. Is there a trick to it or is this a bug? Yesterday I had to join a friend who was already doing the event just to find at the end, what I think is another bug after fighting the dragon. Any help would be appreciated.

The map is on a timer at the end of the timer if your map isn’t already in the fight with Mordremoth he kills everyone on the map and resets the map. Not a big that is what it’s supposed to do.