Repeat Task Won't Go to Next Task

I have created several repeat tasks under a parent tasks, and these are weekly task and all of tasks are same the defer date, but when I pressed completed for the first task, it won’t switch to second task, because the first task when I pressed completed, the defer date of first task will switched to next week, caused first task it won’t completed and system is always detecting the first task that it is not yet completed, so second task won’t bright and showing in perspective.

How do I solved this problem?

You can see the defer time of first task is changed to the next week, but the defer date of second task is still remain the yesterday, and it won’t bright, and also won’t shown in the perspective.

It looks as if you have all the subtasks set as repeating. I think what you want is to have only the parent task set to repeat, and probably also have it (the parent task) set as sequential rather than parallel. That way the subtasks will become available one at a time. When all are completed the parent task will then become available. If you mark it as done it will be recreated for next Saturday together with all its children