I bought a deco yesterday with 3 pcs, ive tried everything to get the ipv6 to work but it wont work, it was working fine on Openwrt and on stock isp modem, ive
tried everything but no hope...its on the latest updated btw.

update:

thats all im getting under ipv6 setting : https://i.imgur.com/mOJvgDY.png

i tried to change connection type to 6to4 and to PPPoe , tried to change all the setting under ipv6 and nothing worked so far, im already using lastes frimware update.
i even tried mac cloning and it didnt do much.