While this may work (I did not try tbh), it is not an ideal solution. The greeter should reflect changes done via gsettings/dconf-editor.
Also, as I checked today, this is not specific to Ubuntu MATE. Same issue exists in LinuxMint when arctica-greeter is installed and enabled. I raised an issue on github. Ref: https://github.com/ArcticaProject /arctica-greeter/issues/17 ** Bug watch added: github.com/ArcticaProject/arctica-greeter/issues #17 https://github.com/ArcticaProject/arctica-greeter/issues/17 -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1900633 Title: arctica-greeter does not honor gsettings changes To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/arctica-greeter/+bug/1900633/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs