I posted to AT&T forum and an amazing user helped me with a new understanding of IPv6 on AT&T.  I only know him as tinslwc.   I credit him with teaching me about IPv6.  

IPv6
Status Available
Global Unicast IPv6 Address 2600:1702:980:25e0::1
Link-local IPv6 Address fe80::eea:c9ff:feb8:84e0
IPv6 Addressing Subnet (including length) 2600:1702:980:25e0::/64
IPv6 Delegated Prefix Subnet (including length) 2600:1702:980:25ef::/64
Global Unicast IPv6 Address 2600:1702:980:25e0::/60

You can create 2600:1702:980:25e8::/64 to 2600:1702:980:25ef::/64

tinslwc did DHCPv6 and can’t get the other 8 /64 subnets to come down. 

2600:xxxx:yyyy:25e1::/64 to 2600:xxxx:yyyy:25e7::/64

We are still working on why? So instead of using /67 blocks, I now have /64 blocks on each interface.