Config device add niv fail

When I use thestrong text following command to add a nic to an instance:

 lxc config device add vm-0CPcG2BlQj nic-G4chwWPzj1 nic nictype=ovn network=test-ovn ipv4.address= name=nic-G4chwWPzj1

The following error occurred

Error: Failed to start device "nic-G4chwWPzj1": Failed setting up device "nic-G4chwWPzj1": Failed adding NIC device: PCI: slot 0 function 0 not available for virtio-net-pci, in use by virtio-net-pci,id=dev-lxd_nic--PsYAzjUju1