So presumably the clients only have link local address i.e., those starting fe80?
As per my the question in the previous post, do you have an IPv6 DHCP server? The 'managed' flag in the IPv6 Router Advertisement being set to 'true' tells the clients to get an address via DHCP. If you don't have an IPv6 DHCP server you should set the managed flag to false, so instructing the clients to use SLAAC (Stateless Address Autoconfiguration).
Did you try the command I put in my previous post?
Regards