Query to get the prepayment Amount Values

Summary

Dear All,
I am creating a BIP report, In which I need to calculate the number of employees processed in the payroll run and sum of total amount in processed in prepayment stage of flow pattern. For the report, I have two parameters - 1. Payroll Run Month-year 2. Payroll Name.
Based on this 2 paramters I have to calculate the count of persons and sum of prepayment amount.
Currently I have created a query to get the desired results, but I am facing problem when I am using personal_payment methods table to join, Some employees are not getting picked, query is skipping some employees. I am attaching the code in below code section.