How to change a monthly paid leaver to weekly NI after termination to make payments after leaving?

Summary:

Our payrolls are processed on a monthly period basis. When leavers require payments after leaving, Payroll are trying to change leavers to weekly NI after termination to ensure that NI is calculated at the weekly deduction rate instead of the monthly, so at the start of the current month they amend the Statutory Deduction calculation card to Irregular periods, number of irregular days to 7, but from April 2024 are encountering processing errors when attempting this, e.g.:

An error occurred when processing autoindirect formula GB_NI_AUTO_INDIRECT
Formula GB_NI_RATE line 220, a local variable was used before being initiated