Some recent update to unstable seems to have broken Xfce4 for me

[Celejar <celejar@gmail.com>]

Hi,

Some recent update to unstable seems to have broken Xfce4 for me: I
can't suspend the the machine anymore. When I try the keyboard shortcut
I've configured (that has worked for years), I get an error popup
window:

Received error while trying to log out
GDBus.Error:org.freedesktop.DBus.Error.InvalidArgs:
Type of message, "(yb)", does not match expected type "(b")

(I've googled this message and found other references to it, but no
clear solution / interpretation:

https://unix.stackexchange.com/questions/626284/thunar-bug-should-i-report-to-xfce-or-ubuntu
https://askubuntu.com/questions/1233288/unable-to-logout-from-guest-session-on-xubuntu-20-04
https://bugzilla.redhat.com/show_bug.cgi?id=1729059
https://forums.freebsd.org/threads/xfce-wont-let-me-log-out-anymore.76968/
https://www.reddit.com/r/xfce/comments/bej4xx/received_error_while_trying_to_log_out/ )

When I try the little "sleepy moon" icon, I get a different popup window:

Failed to run action "Suspend"
GDBus.Error:org.xfce.SessionManager.Error.Failed: Failed to lock the screen.

Any ideas?

Celejar