Interface Configuration - Does this Sound Right?

[LARunnerJ]

I have IPV6 enabled at the WAN level using DHCPV6 with a /56. During the implementation of this further, I have found that enabling IPV6 on a VLAN using "Track Interface" (WAN as the interface) does not actually get an address unless/until the firewall is restarted. This seems unusual to me. My expectation is that once a configuration is applied, it has near-immediate effect. But that doesn't seem to be the case. Even if I disable and re-enable the interface, the assignment doesn't take place.

Am I just completely blanking on something I should be doing?