Edite o arquivo /usr/lib/NetworkManager/conf.d/10-globally-managed-devices.conf
e altere seu conteúdo de:
[keyfile]
unmanaged-devices=*,except:type:wifi,except:type:wwan
para:
[keyfile]
unmanaged-devices=*,except:type:ethernet,except:type:wifi,except:type:wwan
E, em seguida, execute:
sudo service network-manager restart