There has probably been a MAC change and you now have 2 network cards in the OS (atleast that's what it will think).
Can you check the following things and give screenshots:
dmesg | grep eth
Also could you check the content of /etc/udev/rules.d/70-persistent-net.rules
There is a big chance there are 2 devices in this file, remove both entries and reboot the server. This might already resolve the issue.