Today is August 20. This is a burndown graph from this quarter, for a team. They are on track, but looking at the first graph, you'd be asking questions about what is happening that the team seems to be making no progress...

But that would be a very incorrect impression. And the impacts of this bug are the conversations that should not need to happen to reassure managers that the project is still on track.
The second graph is the true picture, based on the best data that Jira Align has at the time.
To prove it, the third graph highlights the penultimate data point on the graph (Aug 18), and the final graph is the next data point (Aug 25).
August 25 is 5 days in the future! There is no valid data for that date yet. The graph should stop at the most recent real data point.
This phenomenon is true for all our teams, in all our TofTs.
(I have looked at information about sprint burndown charts and things that could cause a similar behaviour. None of those causes apply here for quarterly burndown charts.)