No, I don't have this login screen. I suppose because at upgrading time I opted out of password-login. I guess I should activate password-login and restart. Offhand I don't exactly know how to opt in. I tried something else: "remove mate" in simulation mode, just to see what it would do:
Terminal >>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>
fr@hatchbox-2:/media/fr/5E30A37730A354B5/E6500/home/fr$ sudo apt-get -s remove mate
[sudo] password for fr:
Reading package lists... Done
Building dependency tree
Reading state information... Done
Note, selecting 'mate-desktop-environment' instead of 'mate'
0 upgraded, 0 newly installed, 0 to remove and 0 not upgraded.
Terminal End <<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<
"mate-mate-desktop" is installed and checks out. Double-checking:
Terminal >>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>
fr@hatchbox-2:~/logs/install/openpyxl$ dpkg -s ubuntu-mate-desktop
Package: ubuntu-mate-desktop
Status: install ok installed
Priority: optional
Section: metapackages
Installed-Size: 20
Maintainer: Ubuntu Developers [email protected]
Architecture: amd64
Source: ubuntu-mate-meta
Version: 1.225
Depends: alsa-base, alsa-utils, anacron . . . etc.( 75 names)
Recommends: a11y-profile-manager-indicator, acpi-support . . . etc. (183 names)
Description: Ubuntu MATE - full desktop
This package is the complete Ubuntu MATE desktop environment.
.
It is safe to remove this package if some of these packages are not desired.
Homepage: https://launchpad.net/ubuntu-mate/
Terminal End <<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<
Could it perhaps be that the order of lines in "/usr/share/lightdm/lightdm.conf.d" matters, if it is read top down until the first hit. Or should among multiple valid lines all but the applicable one be commented out?