Session-2.scope always times out on logout

Fedora 40 with current updates, including:

• xfce4-session-4.18.4-2.fc40.x86_64
• xfce4-systemload-plugin-1.3.1-7.fc39.x86_64
• xfce4-taskmanager-1.5.7-1.fc40.x86_64
• xfce-polkit-0.3-12.fc40.x86_64

Starting a few weeks ago, every time I attempt to shut down using /sbin/poweroff, session-2.scope times out with message: session-2.scope: Stopping timed out. Killing.

Is there an obvious way to fix this? If not, is there a way to reduce the 45 second timeout of session-2.scope to, say, 5 seconds? I'm shutting down and don't expect that I'd miss anything by not waiting for the full 45 seconds.

Possibly related: I can no longer shut down through the Log Out menu. Nothing happens the first time I click Shut Down. If I try again, I don't get the Log Out menu, but instead get an error message about dbus something. I'll try to capture that and add it here.