reply to graysonf
Your WAN IPv6 subnet mask should be /128, not /64. You should not have to specify anything other than DHCP for that interface for both IPv4 and IPv6.
Not correct. See:»Re: [Business] Unexpected IPv6 address with Business Class stati
I expected to see a /128 on WAN side. Is that because of the /64 on the prefix delegation? Why would that cause the two different LAN side subnets?