My routine is not in that workbook!

The only routine in the workbook you attached with reference to PO is the RunMacroAcrossAllTabs, and in that you have done the line split correctly!!!!

       If xSh.Name <> "Instructions" And _
       xSh.Name <> "Accrual & PO Data" And _
       xSh.Name <> "Tab Name List" And _
       xSh.Name <> "Subtotal Macro Button" And _
       xSh.Name <> "Input Date" And _
       xSh.Name <> "Summary FY19 F1" And _
       xSh.Name <> "EP Local" And _
       xSh.Name <> "Driver Definitions" And _
       xSh.Name <> "EP Global" Then
       xSh.Select 'Run Subtotal Loop on all tabs except these