>I'm wondering how you can deduce from the screenshot that this is happening after all file systems have been unmounted.
I made that comment about "unmounted". It is based on what I see when shutting
down Tumbleweed. In my grub boot line, I have removed "splash=silent". So I
see lots of boot messages and lots of shutdown messages.
When I see that series of "Command failed", I have already seen the unmount
messages, including one "failed to unmount" message (which seems an unimportant
"bug"). Otherwise, what I see is almost identical to the screenshot, except
that the last line is usually "restarting" instead of "powering off".