Software updates on the Ubuntu system will fail because Cockpit on Ubuntu doesn't detect a network connection. To fix this, you must use NetworkManager instead of the default networkd.

You need to be root or sudo root for all these commands. Edit your netplan file in /etc/netplan and add the following two lines under network:.

version: 2
renderer: NetworkManager

Remember that spaces matter in YAML files.

You will then need install network-manager.

apt install network-manager

Disable networkd.

systemctl disable systemd-networkd

Enable NetworkManager

systemctl enable network-manager

Apply your new settings

netplan apply

Profit!