IPV6 Connectivity Issues

[quark]

Hi
I'm new to Opnsense having migrated from Pfsense; which I used for a couple of years.

I have a problem getting ipv6 adressess to my devices. This is what I've done so far:

My ISP; Andrews & Arnold policy on issuing ipv6 addresses is here https://support.aa.net.uk/IPv6#IPv6_on_AAISP_Broadband. In a nutshell upon receiving a valid ppp request, they issue a /128 address of the form  2001:8b0:1111:1111:0:ffff:[your IPv4 WAN in HEX] (NB; this is not my actual address). The ISP then routes the customers preferences; be it a whole /48 block or multiple /64's. So far, I've chosen to receive a single /64 block. To verify that the ipv6 block is routing on my box, I used pcap whilst my isp pinged me. This demonstrated the /64 was routed to the selected interface (NB not the lan interface, but one based on vlans)
The setup of my interfaces is currently identical to that shown in my isp's guide https://support.aa.net.uk/Router_-_OPNsense. I've also unsuccessfully tried their pfsense guide https://support.aa.net.uk/Router_-_PFSense

In conclusion, I'm unable obtain dhcpv6 leases. I'm unable to assign static ipv6 address because this needs a DUID - which I don't have.

I'd much appreciate it If anyone can offer a solution

PS using version 22.1.4