Perhaps the hardware discovery process was a little bit different on each box.
try :
" tail -f /var/log/messages* | grep -i eth " and remove cables (one at a time) or shutdown the corresponding port on the switch side (one at a time) .
verify if the interface that goes down is what you are expecting.
If it does not matches, see if you can try the following:
sk69621 - How to change interface naming on Open Servers running Gaia OS
reorganize the cables to match the naming decided by the OS after the hardware discovery