cluster.yml templating fails when {{ cephadm_admin_interface }} contains hyphens?

[PC-Admin]

So I am trying to set this 'data_t_str' interface as my {{ cephadm_admin_interface }}:

mcollins1@ceph-data-t-mon-01:~$ ip addr show data-t-str
9: data-t-str: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 9000 qdisc noqueue state UP group default qlen 1000
    link/ether 52:54:00:c0:d0:54 brd ff:ff:ff:ff:ff:ff
    inet 10.221.0.11/16 brd 10.221.255.255 scope global data-t-str
       valid_lft forever preferred_lft forever
    inet6 fe80::5054:ff:fec0:d054/64 scope link
       valid_lft forever preferred_lft forever

But with this task (I've added a debug infront):

- name: Debug template variables
  debug:
    msg:
      - "Template variable: {{ hostvars[inventory_hostname]['ansible_facts'][cephadm_admin_interface | replace('-', '_')]['ipv4']['address'] }}"
  ignore_errors: true
  run_once: false

- name: Template out cluster.yml
  vars:
    fsid: "{{ cephadm_fsid if cephadm_fsid | length > 0 else cephadm_fsid_current.stdout }}"
  template:
    src: "templates/cluster.yml.j2"
    dest: "/var/run/ceph/{{ fsid }}/cephadm_cluster.yml"
    owner: root
    group: root
    mode: "0644"
  become: true
  run_once: true

Whether I set {{ cephadm_admin_interface }} as data-t-str or data_t_str, the task fails in the same way with:

TASK [stackhpc.cephadm.cephadm : Debug template variables] **************************************************************************************************************************************************************************************
ok: [ceph-data-t-mon-01] => {
    "msg": [
        "Template variable: 10.221.0.11"
    ]
}

TASK [stackhpc.cephadm.cephadm : Template out cluster.yml] **************************************************************************************************************************************************************************************
An exception occurred during task execution. To see the full traceback, use -vvv. The error was: ansible.errors.AnsibleUndefinedVariable: 'dict object' has no attribute 'data_t_str'
fatal: [ceph-data-t-mon-01]: FAILED! => {"changed": false, "msg": "AnsibleUndefinedVariable: 'dict object' has no attribute 'data_t_str'"}

That's definitely the IP I wanted, but the template fails to recognize that same variable...

If I set cephadm_admin_interface to an interface without hyphens in it, like 'admin', it works. But what if I need to use a interface name that does have hyphens?