Comment 7 for bug 1811580

@ David (dasoto)

nvidia@tegra-ubuntu:/$ ls -la
total 108
drwxrwxr-x 23 ubuntu ubuntu 4096 Oct 30 17:36 .
drwxrwxr-x 23 ubuntu ubuntu 4096 Oct 30 17:36 ..
drwxrwxr-x 22 ubuntu ubuntu 4096 Oct 29 20:31 lib
drwxr-xr-x 5 nvidia nvidia 4096 Oct 29 20:36 media
-rw-r--r-- 1 ubuntu ubuntu 62 May 17 2018 README.txt

The above look very bad too me.

Imho /README.txt shouldn't be there at all.
Not sure why /media is owned by nvidia:nvidia, usually /media is owned by root.
Ditto / and /lib should be owned by root. It is a security vulnerability for unpriviledged user to own these top level directories.

Can you please try this:
$ sudo chown root:root / /lib /media

And check if systemd-tmpfiles works after that?