Changing /etc/subuid is not shown in lxd.log

I’m following sgraber’s article on sharing folders.

I changed /etc/subuid to 1 billion as per his example, and restarted.

t=2018-12-11T16:05:54+0000 lvl=info msg=“Configured LXD uid/gid map:”
t=2018-12-11T16:05:54+0000 lvl=info msg=" - u 0 1000000 1000000000"
t=2018-12-11T16:05:54+0000 lvl=info msg=" - g 0 1000000 1000000000"

but now if I change it again to a different value, and restart LXD, it does not change.
It is always stuck now at 1 billion.

Can anyone suggest why, and how to force a change?
Is this 2017 article still valid for 3.7?

$lxc --version
#systemctl restart snap.lxd.daemon.service
#tail -f /var/snap/lxd/common/lxd/logs/lxd.log
Host: Ubuntu 18.10

Oh, OK
I changed my search terms and found this
(Problems with id mapping with LXD 3.0.0)
that explains it!!