Why nmcli connection up reports "Error: Connection activation failed: No suitable device found for this connection (device lo not available because device is strictly unmanaged)" ?

Issue

• Encountering errors when attempting to bring the device up using nmcli con up.

[root@localhost ~]# nmcli con up ens1
Error: Connection activation failed: No suitable device found for this connection (device lo not available because device is strictly unmanaged).

• After server patching and reboot, unable to bring up the connection.