More than 5,000 Afghans brought to the US after American forces withdrew from the country got flagged for “national security” issues, Department of Homeland Security data obtained by The Post reveals. In all, the feds uncovered “potential derogatory information” on a total of 6,868 people who came from Afghanistan as part of President Biden’s Operation Allies Welcome in 2021. Of that number, 5,005 came up with a national security concern, while 956 people had “public safety” concerns and 876