OK – so you were using the term Dashboard to mean all the admin as opposed to the dashboard page itself. That makes it easier.
The stats area at the bottom is, as @mr-papa said, updated on a scheduled basis as part of optimisation processing. The default schedule is, I believe, once an hour. This is handled by the core WordPress ‘cron’ process along with many other tasks from WP itself, SP and possibly other plugins. It is not unknown for the WP Cron system to stop working – or – to lose scheduled events supplied by plugins.
One quick and simple way that most usually should jog things back in to life is to deactivate the core Simple:Press plugin (NOT Uninstall – take care!) and then when the WP plugins page reloads, activate it again. This should cause all cron schedules to be recreated and the forum stats to then continue to be updated as before.
I would suggest trying this as the first step – and if, after an hour the stats have not been updated come on back and we can rethink.
Of course, always useful to do this when there are none of your users on the forums!
