With ubuntu-mate i need to run a workaround for new ubuntu users that complain about not connected (while internet works)
There is a line missing in the "/etc/netplan/00-installer.yaml"
With "renderer: NetworkManager" added the eth0 status is displayed.
Would be nice if this goes with the installer on the default setup.
this bug percist from 2019.
https://askubuntu.com/questions/1156990/netplan-config-not-working!