Can't ping successfully via IPv6 both Dynamic & Static.

Can't ping successfully via IPv6 both Dynamic & Static. (dhcp-4.4.1 is unnormal, dhcp-4.3.6 is normal)

1. Connect the SUT to the Client PC which was configured the IPv6 DHCP services.
2. Set the LAN channel 1,2,3 channel to "IPv6 DHCP" mode.
3. All the LAN channel are received the dynamic IPv6 IP successfully.
4. But we can not ping through these IPv6 IP from the Client PC. We also tried with the "IPv6 Static" mode, the result are the same.

Thanks