The dual progress bar shows progress of execution one or more background tasks (sub-tasks).
The total progress is the progress of the tasks, where the second progress bar shows the progress of the current background tasks being executed.

Current behavior is that the total progress-bar counts the sub-task as completed before it's even started.
If there is sub-single task to be completed , it immediately jumps to completed.

Expected behavior
The progress of the sub-tasks, steers relative progress of total.
So if there are 4 sub-tasks to perform.
So the total progress is calculated as:
total-progress = subtasks completed * (100% / number-of-subtasks) + progress-current-subtask * (100% / number-of-subtasks)