Summary of Payments do not match Payroll Activity Report

Hello,  I have 2 employees who Summary of Payments do not match the Payroll Activity report.  On one it is not reporting the Gross Payments at all.  On the other employee, it is missing random Gross Payments plus PAYG witholding and Salary Sacrifice and Super guarantee.  It is like is it missing several payes for this person.  Help needed please.