Adding address=127.0.0.1 to the server.xml Connector tag got tomcat9 to respond again. There was not previously an address attribute on that tag.
However, it was responding previously without that, and I have another server (like a staging) that is setup using the exact same config (running the exact same Ansible provisioning scripts) that does NOT require that address change. I do not have high confidence that this is a lasting solution.