Trouble with getting ipv6 working

[icsy7867]

My ISP seems to have a fairly simple ipv6 deployment.  However I can ping out from my WAN, but I cannot from my LAN interface.

DHCPv6
Request only an ipv6 prefix
It seems they only offer a /64
And I send this as a preix hint.

I think set one of my LAN interfaces track -> WAN.  For ease, I set the router advertisements to unmanaged (But have tried managed and assisted as well)

My WAN still seems to pull an ipv6 address and I also see the /64 prefix in the overview page.  My LAN devices also seem to pull IPv6 addresses.  However I can ping out via IPv6 and my WAN,  but my LAN devices fail.  Usually due to no route to host, or a "Beyond scope of source address" message.

I have ipv6 in/out ANY to ANY rules on WAN and LAN for testing.

One thing I found strange, was that my WAN interface still receives an IPv6 address, but it appears to be using another prefix.  My pulled prefix is:
XXXX:XXXX:XXXX:f735::/64

And my WAN pulls an ipv6 address of
XXXX:XXXX:XXXX:12e3:2e0:67ff:fe2c:65bc/64

Is it normal for this ipv6 to be outside of the /64 block?  While I am trying to figure out how to add working ipv6, I found this odd.

Thanks!