Multi-registrations/Family Registrations work differently than Individual registration options.
The confirmations generated for Multi-Registrations/Family Registrations do not use the Advanced Confirmation Template.
Instead, they use a combination of preset hard coded text and the information that is entered in Webinfo Checklist > Event Text, under the section labeled:
Simple Confirmation Setup
Registration Confirmation Text and Details
The primary registrant and all Team/Family members will receive a confirmation that is formatted in this way, each with their login information and links to their respective pages.