Closed the tab mid-briefing? Audience Research does not make you pay twice.
A briefing is built in four steps, and the work is saved after each one. Here is what the Unfinished and Stopped labels on your saved list mean, what Retry this step actually re-runs, and why you should reopen the old briefing instead of starting a new one.

You press Generate the briefing, the progress list starts ticking, and then your laptop closes, your train goes into a tunnel, or you remember a call and shut the tab. The natural next move is to open a new briefing and type everything in again.
Don't. The old one is still there, and it is waiting for you.
A briefing is four requests, not one
The progress screen shows four lines. The first three are research passes: reading up on how the industry is built, looking at who works there and who they compete with, and digging into what people complain about and worry about. The fourth is writing your briefing.
Each line is its own request, and each one saves what it found before it hands off to the next. The page you are looking at is what moves the job forward. That is why the screen says you can leave and that your progress is saved, and why leaving stops the job rather than ruining it.
Read the badges on your saved list
Open the saved briefings page and every briefing is listed newest first, with a date. Finished ones carry no badge. The others do: