Cannot close POs in workbench due to project status

Hi,

Question below is relate dto POs that are created for grants project. We use the Workbench to close POs for a specific chartstring. However, if the project status is 'Semi-closed' we receive the below message:

Project status is changed from 'Approved" to 'Semi-closed" when we don't want additional requisition/POs to be created for the grant project in question. Can you please clarify what flag(s) are updated on the PO side when the project status changes? Is there any way to side-step this since we need to have the project in "semi-close' status to prevent new transactions but Billing & Receivables can continue finalizing their processes.