I believe that the bolded text below should be "failure" instead of success.
- name: "MEDIUM | WN19-AU-000330 | PATCH | Windows Server 2019 must be configured to audit System | IPsec Driver failures."
ansible.windows.win_shell: AuditPol /set /subcategory:"IPsec Driver" /failure:enable
when: "'Success' not in wn19_au_000330_audit.stdout"
Auditpol is not getting configured to set for failure checks for this reason.