Oddball behavior on laptop with Xubuntu 22.04.1

[MR ZenWiz]

I run this on all my machines, and tonight my primary laptop started
doing some seriously strange things. I had just exited Chrome, but it
won't restart - I'll get to that in a moment.

When I try to shut the laptop down, it sits there and appears to do
nothing. When I try to shut it down again (both using the menu ->
power/logoff -> shut down), I get a window that says this:

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

The only way I can shut down the machine is the power button, and the
last time I tried this, it rebooted after the shutdown.

When I tried to run chrome manually, I got this:

21:08 [admar at marLG17Z90N:~/Downloads] $ /opt/google/chrome/google-chrome
[4299:4299:1011/210850.270572:ERROR:process_singleton_posix.cc(1038)]
Failed to create socket directory.
[4299:4299:1011/210850.270678:ERROR:chrome_browser_main.cc(1440)]
Failed to create a ProcessSingleton for your profile directory. This
means that running multiple instances would start multiple browser
processes rather than opening a new window in the existing process.
Aborting now to avoid profile corruption.
21:08 [admar at marLG17Z90N:~/Downloads] $ libva error:
vaGetDriverNameByIndex() failed with unknown libva error, driver_name
= (null)

21:08 [admar at marLG17Z90N:~/Downloads]

I don't know what any of that means and I didn't see anything useful
from a web search.

Another weirdness I had was a log of "no space on device" errors.
Here's what df showed:

21:00 [admar at marLG17Z90N:~/Downloads] $ df
Filesystem     1K-blocks      Used Available Use% Mounted on
tmpfs            1599400      2064   1597336   1% /run
/dev/nvme0n1p5  78165676  74215084         0 100% /
tmpfs            7996988         0   7996988   0% /dev/shm
tmpfs               5120         4      5116   1% /run/lock
/dev/nvme0n1p6 320892768 194693608 109825504  64% /home
/dev/nvme0n1p1    262144     67424    194720  26% /boot/efi
tmpfs            1599396        76   1599320   1% /run/user/1000
21:08 [admar at marLG17Z90N:~/Downloads] $

I had no trouble ssh'ing into the laptop, or rsync'ing out. I found
that my kern.los and syslog were insanely huge, so I deleted them
(without looking - foo). That di not seem to take effect until after I
rebooted into Windows, then rebooted back to Xubuntu.

Suddenly it has lots of space and an enormous auth.log, which contains
37Gb of this error set:

Oct 11 21:31:09 marLG17Z90N systemd-logind[612]: Suspending...
Oct 11 21:31:09 marLG17Z90N systemd-logind[612]: Unit suspend.target
is masked, refusing operation.
Oct 11 21:31:09 marLG17Z90N systemd-logind[612]: Failed to execute
suspend operation: Permission denied

Can anyone shed any light on this?

Thanks.

Mark