No lock screen after suspend with MATE

[stephematician]

Expected behaviour

Screen/session should be locked after awaking from suspend

Actual behaviour

Session is unlocked.

Steps to reproduce the behaviour

1. UbuntuMATE 24.04.1 clean install or live boot.
2. Select ⏻ -> Suspend
3. Wake up laptop.

Distribution and package version

Ubuntu MATE 24.04.1

mate-desktop: 1.26.2-1.1build3
ayatana-indicator-session: 24.2.0-1build2

Link to bugreports

https://bugs.launchpad.net/ubuntu-mate/+bug/2085580
mate-desktop/mate-session-manager#315

[stephematician]

After further investigation, this looks like the intended behaviour? Rather than use the session manager (e.g., in my case, MATE) to handle the suspend operation, ayatana-indicator-session calls systemd-logind directly to suspend.