Update subtask status based on another subtask status

[Lydia M]

I would like the status of one subtask to automatically update the status of another subtask in the same Parent.

I have a Parent with subtask A and subtask B.

Designers use A and update the status to Generating Script. I want this action to automatically update B to the same status.

Currently, the Designer has to update the status in both subtasks. It would be more efficient if updating A would automatically update B to the same status.

I have looked at post-functions and none of them seem to create the desired result.