So looking at the new 5.11.10 release, looks like they have added ipv6?
from 5.11.5 in the release notes?
Add subnet for IPv6 networks in Networks Table.
I am currently running 5.10.21 which is not viable direct upgrade.. So can not test for sure until I get on 5.11.10, but you might want to try 5.11.10 if you want ipv6 with guest policy enable. But not captive portal.
