Truenas Scale Service Announcement not broadcasting domain name

I want to access my Truenas system using its FQDN (e.x. truenas.mydomain.com) on IPv6. I have the domain set in the Network settings and all the Service Announcements enabled (netbios, mdns, ws-discovery) however, I can only resolve truenas.local. How do I get those services to broadcast the full domain name?

My ISP constantly changes the IPv6 prefix so I can’t add a static AAAA record to my local DNS.