Trouble shooting is par for the course. At this point, start with the laptop. Can you get that laptop to connect to the internet? Configure this laptop with all static network configurations. Static IP, Subnet, Gateway. Make sure you can get this thing on the network. Connect the laptop into a switch, plug one computer that you want to clone into that switch and set it to boot via PXE. If you know the linux laptop can connect to the network and you know that the other computer can PXE boot, and you've got them on their own switch where no other DHCP server or firewall can interfere, then you move on to troubleshooting your clonezilla DHCP setup. The easiest way that Clonezilla can be set to configure its server is to do the default values settings with: sudo /opt/drbl/sbin/drbl4imp
Anytime you have to "reset" the clonezilla sytem, try that command line to get you back to a known good state.
If you can't ever seem to get the chosen computer to PXE boot and talk to the clonezilla server, can you get some OTHER brand of computer with a DIFFERENT brand of network card to connect to the clonezilla server?
Just troubleshoot piece by by piece, Can I get the clonezilla server on the network? Put the computers on an independent switch with no other devices to eliminate switch and port blocking issues, then can I find one machine that is known to be able to PXE boot? Get a clear clean path of communication from server to switch to host computer. Are those cables good? Go back and reset the clonezilla server if needed. You CAN get it to work.
Don't get too frustrated by the fact that it won't work out of the box, expect a bit of fighting, and expect to win too.