Strange middle of the night behavior

[MR ZenWiz]

My desktop recently started logging me out in the middle of the night
when I'm asleep.  I have no idea why or muc of where to look.

I checked the Xorg.0.log, and all it shows for EE entries is that my
mouse and keyboard are occasionally slow to respond (!).  I can't read
the timestamps in there (yet) so I'm not sure to what time these
correlate.

I've looked through the syslog, and there are some strange entries,
and I just found this sequence:

Nov 22 01:58:02 marbase kactivitymanagerd[619486]: The X11 connection
broke (error 1). Did the X11 server die?
Nov 22 01:58:02 marbase pulseaudio[519046]: X11 I/O error handler called
Nov 22 01:58:02 marbase at-spi-bus-launcher[518632]: X connection to
:0 broken (explicit kill or server shutdown).
Nov 22 01:58:02 marbase pulseaudio[519046]: X11 I/O error exit handler
called, preparing to tear down X11 modules
Nov 22 01:58:02 marbase systemd[2016]: plasma-kglobalaccel.service:
Main process exited, code=exited, status=1/FAILURE
Nov 22 01:58:02 marbase systemd[2016]: plasma-kglobalaccel.service:
Failed with result 'exit-code'.
Nov 22 01:58:02 marbase systemd[2016]: xfce4-notifyd.service: Main
process exited, code=exited, status=1/FAILURE
Nov 22 01:58:02 marbase systemd[2016]: xfce4-notifyd.service: Failed
with result 'exit-code'.
Nov 22 01:58:02 marbase systemd[2016]: xdg-desktop-portal-gtk.service:
Main process exited, code=exited, status=1/FAILURE
Nov 22 01:58:02 marbase systemd[2016]: xdg-desktop-portal-gtk.service:
Failed with result 'exit-code'.

I don't know what those mean.  They also appear in the older logs on
Nov 20 and Nov 12.

There are also occasional sequences like this:

Nov 20 11:31:27 marbase anacron[530025]: Anacron 2.3 started on 2021-11-20
Nov 20 11:31:27 marbase anacron[530025]: Normal exit (0 jobs run)
Nov 20 11:31:27 marbase systemd[1]: anacron.service: Deactivated successfully.
Nov 20 11:45:27 marbase systemd[1]: Starting Refresh fwupd metadata
and update motd...
Nov 20 11:45:27 marbase dbus-daemon[1383]: [system] Activating via
systemd: service name='org.freedesktop.fwupd' unit='fwupd.service'
requested by ':1.1264' (uid=62803 pid=530499 comm="/usr/bin/fwupdmgr
refresh " label="unconfined")
Nov 20 11:45:27 marbase systemd[1]: Starting Firmware update daemon...
Nov 20 11:45:27 marbase fwupd[530505]:
ERROR:esys:src/tss2-esys/esys_context.c:69:Esys_Initialize()
Initialize default tcti. ErrorCode (0x000a000a)
Nov 20 11:45:27 marbase dbus-daemon[1383]: [system] Successfully
activated service 'org.freedesktop.fwupd'
Nov 20 11:45:27 marbase systemd[1]: Started Firmware update daemon.
Nov 20 11:45:27 marbase systemd[1]: fwupd-refresh.service: Deactivated
successfully.
Nov 20 11:45:27 marbase systemd[1]: Finished Refresh fwupd metadata
and update motd.

Not sure if this is serious, and they map to all times of the day, so
I don't believe they're a big threat.

This is Xubuntu 21.10 running on a Ryzen 9 5950 with 32GB or RAM and
an ASUS TUF x570 Pro motherboard, if that's any help.

Comments/suggestions most welcome.

Thanks.

Mark