i am unable to do VNF nic Mappings

<img width="1226" height="609" alt="Image" src="https://github.com/user-attachments/assets/39ea57de-599f-4fce-ac47-752815a4fbe5" />

i am creating a pfsense vnf in cloudstack but when i select my networks later i am trying to map my nics to vnf but it is not allowing me to map it.......earlier it was working but now i am not able to do it ............anyone help??