Custom DynDNS and IPv6

[lupilo]

Hello,

my OPNsense is running behind a router (FritzBox with public IPv4+IPv6 address).
OPNsense is configured to get it's WAN IPv6 address via SLAAC. The "Interfaces: Overview" page looks like this:

Code: [Select]

IPv6 link-local fe80::98ce:7fff:fe50:ded4/64
IPv6 address         fd00::98ce:7fff:fe50:ded4/64
                        2003:c4:4f09:670f:98ce:7fff:fe50:ded4/64
So far so good
I'm using the os-dyndns plugin to trigger some "Custom (v6)" DynDNS-services.
According to the documentation, I'm allowed to use "%IP%" within my update url:

http://[fd00::a8a7:e4ff:fe4e:c106]/update.php?ipv6=%IP%&domain=my.domain

Until recently, everything was working fine configured like this. This has changed recently (I assume due my FritzBox replacement).

%IP% reprececents now no longer my public IP address 2003:c4:4f09:..., instead the fd00:.. entry is used.
I'm wondering, if there is any way to fix this behavior?
Is it possible to manually sort/prioritize the order of my IPv6 address within OPNsense?