GRN with Inbound delivery issue

Dear experts, User has created PO with Confirmation Control Key "GRN with Inbound Delivery". Then user has made GRN without creating the Inbound Delivery. How it is possible? And when we tried to cancel the GRN, system not allowing to cancel the GRN document sine the Confirmation Control Key "GRN with Inbound Delivery" is selected.

Getting below error when tried to cancel the document "Message no. M7036"

No goods receipt possible for purchase order 5200000368 00010

Please guide me on this.

Note: We have tried replicating the same in Quality system, system does not allow to make GRN without creation of Inbound Delivery.