Comment 7 for bug 1887744

> Sorry, turns out the /etc/systemd/system service file needs to be a
> symlink to trigger the bug. This will do it:

aha! and not only a symlink, but the target of the symlink needs to be outside the normal systemd service path locations, or it will reject loading it:

root@lp1887744-f:/etc/systemd/system# ls -l test*
lrwxrwxrwx 1 root root 13 Jul 20 18:17 test.service -> test@.service
-rw-r--r-- 1 root root 76 Jul 20 18:14 test@.service

root@lp1887744-f:/etc/systemd/system# journalctl --no-pager -q -b --grep test.service
Jul 20 18:17:33 lp1887744-f systemd[1]: /etc/systemd/system/test.service: symlink target name type "test@.service" does not match source, rejecting.