Tomato Shibby IPv6 ping from router works, ping from LAN does not

Hello I am having a hard time setting the IPv6 in my Asus RT-N16 router with Tomato by Shibby (version 1.28.0000 MIPSR2-131 K26 USB AIO).

• My internet provider recently installed the Optical Network Terminal (ONT) in my home
  
• When I connect the pc directly to the ONT, everything works perfectly and on the ipv6 test sites I get the maximum score, ping to ipv6,google,com works
  
• When I connect the router to the ONT, router gets both IPv4 and IPv6 address correctly and even the...

Tomato Shibby IPv6 ping from router works, ping from LAN does not