It's synchronised. I think. ;D
Anyway, the first and most important thing is, can you confirm that the player is a member of the group in question, and not the leader? And is it impossible for all the group (except the player) to be killed before the cutscene happens?
Assuming the answer to both of these is yes (and that waypoints are therefore appropriate) then probably what's going wrong is that the triggers and waypoints are not quite in the right order. If your cutscene is happening at a waypoint then you don't need a trigger at all, I would recommend using a script waypoint: there is an excellent tute somewhere, I think it was by General Barron. (I'm also assuming you are using a camera script rather than just the crappy trigger-based camera. If not, learn the camera scripting - it doesn't take long to learn and is much much easier than using triggers.)
To answer the basic point directly, remember that setting a waypoint field to aware or whatever makes the group go into that behaviour as soon as they complete the previous waypoint. Sometimes you need to add extra waypoints to the sequence to make everything happen the way you want. If waypoints are close together the group can complete several without actually moving.
If the group leader is not moving it may be that he is getting stuck for some reason, or perhaps the waypoint has not been completed properly. If you're having trouble with a waypoint sequence its worth removing the triggers from it to see if it runs smoothly.