Recently we are upgrade the jira 8.20.6 version,In kanban board when select the quick filter ,The Done status tickets showing 5 out of 399,In the bottom of the done column We're only showing recently modified issues. Could you please help on this issue.
I have shared the screenshots kindly check it once.
please verify "Hide completed issues older than" parameter in your Board Configuration - General section.
More information available in the following article https://confluence.atlassian.com/jirakb/when-configuring-a-kanban-board-and-setting-the-option-hide-completed-issues-older-than-in-general-and-filter-filters-other-issues-in-other-columns-besides-the-one-in-the-done-column-993924923.html
Hope this helps,