A consulting company that employs Oracle Cloud Infrastructure (OCI) architects has successfully completed resource migration from Microsoft Azure to OCI, and no longer requires the OCI FastConnect circuit to Azure. The project manager has asked you to delete all resources involved in this inter-cloud connectivity. From the Azure side, you delete the Resource Group. After a while, you notice that all Azure resources have been deleted, except for the Azure ExpressRoute circuit.
What could be a potential reason for this issue?