I don't know if you are still tracking this problem but, I have encountered this problem too and the solution that works consistently for me when I do clone a Debian guest is as follows:

1. Prior to cloning, shutdown the vm to be cloned.
2. Clone the vm (make sure you select "Reinitialize the MAC address of all network cards")
3. Boot the clone vm and edit the /etc/udev/rules.d/70-persistent-net.rules as root. Remove all references to interfaces. These will be rebuild automatically the next time you boot.

That's it! Hope this helped.

raydos

I don't know if you are still tracking this problem but, I have encountered this problem too and the solution that works consistently for me when I do clone a Debian guest is as follows:

1. Prior to cloning, shutdown the VM to be cloned.
2. Clone the VM (make sure you select "Reinitialize the MAC address of all network cards")
3. Boot the clone VM and edit the /etc/udev/rules.d/70-persistent-net.rules as root. Remove all references to interfaces. These will be rebuild automatically the next time you boot.