Some days ago, my Ubuntu warned me that could be upgraded to 22.04, the new LTS version, called Jammy Jellyfish. I thought that was the moment and I proceeded. I had to say that I faced several issues, like some issues with Python3.10 that affected many applications (you know, Ubuntu uses Python a lot) but it was easy to solve just making some re-installation. But I was really upset when I saw that my Ethernet interface was not working.

Ubuntu settings even did not detect the wired connection, but the interface was there:

$ sudo lshw -C network
  *-network DISABLED
       description: Ethernet interface
       ....
       logical name: enxe4b98
       ...

Therefore, Ubuntu had to start the interface at boot time and setting it up using DHCP.

/etc/network/interfaces

# interfaces(5) file used by ifup(8) and ifdown(8)
auto lo
iface lo inet loopback

+# workaround for ethernet
+auto enxe4b98
+iface enxe4b98 inet dhcp

And restart NetworkManager:

$ sudo systemctl restart NetworkManager

The interface was already detected by Ubuntu settings, but it was unmanaged:

$ nmcli device
DEVICE           TYPE      STATE        CONNECTION 
enxe4b98         ethernet  unmanaged    --

We could apply a workaround to NetworkManager in order to make it work:

/etc/NetworkManager/conf.d/allow-unmanaged-devices.conf

[keyfile]
unmanaged-devices=*,except:type:wifi,except:type:gsm,except:type:cdma,except:type:ethernet

And restart NetworkManager

$ sudo systemctl restart NetworkManager

Now, your Ubuntu will be connected to Internet using Ethernet.

$ nmcli device
DEVICE           TYPE      STATE        CONNECTION 
enxe4b98         ethernet  connected    enxe4b98