Requisition Without Agreement Link

Hi everyone, has anyone faced this scenario?

I have an item that's part of an existing Blanket Purchase Agreement but in some cases, I need to create a requisition without linking it to the agreement — the "Negotiated" checkbox should be selected, because I need to create the PO automatically and the requisition should not default to the BPA,

The goal is for this requisition to automatically generate a PO, but without any agreement reference.

Has anyone found a way to configure this ?
I’ve already tried manually removing the source agreement, but the system keeps linking it back automatically.

Any suggestions would be appreciated!