deploy instructions on charmhub don't configure default checks on ubuntu charm

I've followed the deployment instructions on https://charmhub.io/nrpe as follows:

juju deploy ubuntu
juju deploy nrpe
juju deploy nagios
juju add-relation ubuntu nrpe
juju add-relation nrpe:monitors nagios:monitors

I'm running this using the LXD provider on juju 2.9.23. The deployment instructions state "If joined via the juju-info relation the default checks are configured". However, I don't see the default checks for the ubuntu unit, only "ssh" and "juju-ubuntu-0-check_conntrack". I'd expect to see disk checks, memory checks, load checks, etc.. I do see those for the nagios instance itself.