It seems that with Supplementary pay runs, when the payroll summary is finalized and payslips are 'pushed' that this results in ALL payslips for the main payroll run being re-published on MEPW. The only way around this is to individually push each payslip in the employee profile I would suggest support fix this issue, to allow supp run payslips to be published immediately on finalization without resulting in duplicates. The current support team ticket suggested to reopen and re-publish again to do this but this is a temp workaround, the system should allow for supp payslips to be published at once easily.