Why would there be? Pluribus doesn't issue security clearances, the customer agency (in this case the NSA) does. It would be up to the NSA to do any additional background checks/vetting/polygraphs regarding security clearance for any contractors. Working for a contractor/switching jobs is hardly suspicious activity, so the NSA would have no reason to investigate her. Likewise Pluribus had no reason to be suspicious, so the most they'd do beyond the standard corporate background check is call up the NSA to confirm her clearance was active. At the end of the day even the NSA doesn't have the resources to be constantly vetting 100,000+ employees and contractors.