I have ipv6 tunnel from HE (also tries NetAssist) set up on Asus RT-N66U with Shibby v132. IPv6 works good on my Linux (Arch) server (which is connected by wire) and doesn't work on Windows 8.1 or Android devices, which are connected by wireless. I can ping the gateway from all the devices, but can't ping anything further from Windows.
I recall I had IPv6 working before, but disabled it because of issues with WhatsApp message delivery.
Could provide any other information. Hope someone could help me to deal with this problem!