fix(Core/Movement): resume waypoint movement after casting interruption (#25269)

Co-authored-by: blinkysc <blinkysc@users.noreply.github.com>

src/server/game/Movement/MovementGenerators/WaypointMovementGenerator.cpp

@@ -367,6 +367,7 @@ bool WaypointMovementGenerator<Creature>::DoUpdate(Creature* creature, uint32 di
         creature->StopMoving();
         _lastSplineId = 0;
         _smoothSplineLaunched = false;
+        _hasBeenStalled = true;
     }
 
     // Set home position to current position.