Login to Azure Portal https://portal.azure.com.
Locate and stop the a VM that is having an NIC issue.
Click on Networking > Click Network Interface link.
Take the screenshot of the old NIC for reference to create the new NIC.
Now go to Azure Home search Network Interface and click on Create.
Fill in all the details below referring to the above old NIC screenshot.
Goto New NIC > Click on Network Security group and select the group referring to the old NIC screenshot.
Go back to VM > Networking > Attach network interface.
Select the new NIC from the drop-down menu and click ok.
Now click on Detach network interface select the old NIC to remove and click ok.
Now start the VM and check boot diagnostics. The network should be available now.
