NetworkManager: static IP address for one of the NICs, make sure the settings is assigned to the correct NIC

Set the second NIC to unmanaged in NetworkManager's command line interface (nmcli)

Define the second NIC in /etc/interfaces to be brought up without IP address

Check settings in /etc/interfaces/interfaces.d/orange and /etc/NetworkManager/NetworkManager.conf

Connect to the server's second NIC as bridged

NetworkManager: static IP address

Check settings in /etc/interfaces/interfaces.d/ and /etc/NetworkManager/NetworkManager.conf