When viewing the archive tab, the first concern type (called "Report1" by default) is not displayed when you click its second-level tab. Instead, all entries are shown. This is due to the reporttype_id for this concern type being 0 in code, which is seen as empty by line 538 of ilp_dashboard_archive_tab.php, causing part of the WHERE clause to be removed from the query.
Changing the empty() check to a !== false fixes the problem.