task props issue fix

src/components/gantt/gantt.tsx

@@ -54,6 +54,10 @@ export const Gantt: React.SFC<GanttProps> = ({
   const gridWidth = dates.length * columnWidth;
   const ganttFullHeight = ganttTasks.length * rowHeight;
 
+  useEffect(() => {
+    setGanttTasks(tasks);
+  }, [tasks]);
+
   // scroll events
   useEffect(() => {
     const handleWheel = (event: WheelEvent) => {

src/components/gantt/task-gantt-content.tsx

@@ -270,7 +270,7 @@ export const TaskGanttContent: React.FC<TaskGanttContentProps> = ({
           return task.barChildren.map(child => {
             return (
               <Arrow
-                key={`Arrow from ${task.id} to ${tasks[child].id}`}
+                key={`Arrow from ${task.id} to ${barTasks[child].id}`}
                 taskFrom={task}
                 taskTo={barTasks[child]}
                 rowHeight={rowHeight}