when you pin a report visual to a dashboard tile the meta data connection gets cut. Whatever changes you do to the report after that will not reflect in the dashboard tile. So most likely your source data has changed, then you adjusted your reports, and expected the dashboard tiles to adjust as well. But as mentioned above that will not happen. In order to propagate meta data changes from report visuals to dashboard tiles you need to delete the tile and re-pin the visual.
It is irrelevant (mostly) if your report page is hidden or visible.