I have been allocated a /56 IPV6 from my ISP. I have DHCPv6 setup on the pppoe0 interface (PPPoE over VDSL2) and a /64 from the pool on the LAN interface (Vlan40).
When I use address auto config, it works fine.
When I try to set a static IP on the host and Vlan40, it works for a few minutes to an hour (aprox) and then refuses to work via IPV6. At that point I can't even ping the router IPV6 LAN address.
Additionally, "route -A inet6" on the client (Linux desktop) shows all the route entries are still there.
I have tried disabling both auto config and then ND and this does not fix the issue.