Blocking ICMPv6 on PPPoE interface

It seems to block the ICMPv6 134-137 on the pppoe interface, so the default ipv6 gateway of the pppoe interface disappears randomly. The dual stack ipv4 on the pppoe seem not be affectted, LAN dualstack ipv6/v4 neither.

You need to create allowed global rules for those ICMPv6 type messages.