Invoices Submitted for Services Rendered on an Expired Contract

I have been re-assigned a firm-fixed type contract for the installation of new conference room equipment. The contract consisted of a base period and 2 twelve-month option periods. During the last Option Period (3/30/2022 – 3/29/2023), the Contractor experienced unforeseen delays as a result of supply chain issues with the product manufacturer. The Contractor informed me that they had communicated these unforeseen delays and provided documentation to the former COR and CO and had requested an extension. The Contractor indicated that the previous CO informed their company that the contract would be extended in order to provide sufficient time for their company to complete the installation tasks. Upon receiving the contract re-assignment, I reviewed the contract file documents and noticed that the contract period of performance ended on March 29, 2023. No mod had been executed by the former CO to extend the period of performance.

The Contractor and the newly assigned COR contacted me to inquire about the reason for the rejection of the Contractor's invoice. Upon reviewing the invoice, I noticed that the Contractor billed for services rendered beyond 3/29/2023. I met with my supervisor who had been re-assigned this contract to her branch to inform her that the contract period of performance ended and no documentation existed extending the period of performance. After further discussions, my supervisor recommended that I extend the contract so that the contractor could be paid for the services rendered. Since the government received a benefit from these services, my supervisor recommended that I document the file. How is it possible that a contract that ended 6-months ago be extended? Please advise.