Check your grid pause time. Might be possible your timing is off. To test waypoints out, in your NPC's script file try this:
Code:
sub EVENT_WAYPOINT_ARRIVE {
quest::shout("I have arrived at Waypoint $wp.");
}
sub EVENT_WAYPOINT_DEPART {
quest::shot("I am departing Waypoint $wp.");
}
Also, check that your grid numbers are sequential. It is possible that the entries are not in order.