When you make updates to specific reports that drive your dashboard panels, these do not update the dashboard panels. The fix is to delete the panel and re-add the newest version of the report. This makes building dashboards much more difficult unless you know the exact requirements for the reports and they do not change.
In addition, making a modification to a panel in the dashboard, creates a secondary report "(dashboard panel)" (separate from original). This creates duplicate panels and makes it hard to manage all of your panels.
Thanks for sharing this idea and the challenge you are having with Dashboards.
Today, when you add a view to a dashboard, you will be working with a copy of the view. This lets you customize the report, chart, or roadmap to fit your dashboard without affecting the original report. You will know you are customizing the duplicate view if you see (dashboard panel) after the report's name.
It sounds like you would prefer the panel to link directly to the original. We will continue to monitor feedback on this idea.