I've imaged about 30 notebooks with the same USB-key (always the same kernel too, the 4.16.1x64) successfully.
With one I have now the problem that I can't boot from the USB-key completely. The device boots to the menu, then it doesn't matter if I choose "Clone Deploy" or "Client Console", the notebook always reboots after pressing enter.
I've tried 2 other kernels (4.13.2x64 and 4.5x64) and a different usb-key with exactly the same failure.
I've also tried to "play" with the BIOS settings (secure boot, fast boot, UEFI/Legacy,...) without success.
With the same usb-key and a windows installation image, the notebook boots without problems, so the failure seems to be not the notebook.