How do I set up radvd correctly?

[vladns]

I have radvd configured for ipv6 ads for "normal" internet (clearnet), config:

interface br0
{
  AdvSendAdvert on;
  MaxRtrAdvInterval 60;
  prefix ::/64
  {
    AdvValidLifetime 600;
    AdvPreferredLifetime 120;
  };
  RDNSS local_ipv6_address
  {
  };
};

When I add the config, as recommended here https://yggdrasil-network.github.io/configuration.html#advertising-a-prefix, ipv6 stops working for clearnet. In addition, the interface (br0) loses its ipv4 address after executing the command:

ip link set dev br0 down && ip link set dev br0 up

The final config was like this:

interface br0
{
  AdvSendAdvert on;
  MaxRtrAdvInterval 60;
  prefix ::/64
  {
    AdvValidLifetime 600;
    AdvPreferredLifetime 120;
  };
  RDNSS local_ipv6_address {};

  AdvSendAdvert on;
  AdvDefaultLifetime 0;
  prefix 300:abcd:abcd:abcd::/64 {
     AdvOnLink on;
     AdvAutonomous on;
     };
     route 200::/7 {};
};

Where could the problem be?

[iav]

my working config file:

interface wlan0
{
     AdvSendAdvert on;
     AdvDefaultLifetime 0;
     prefix 301:aaaa:aaaa:aaaa::/64 {
         AdvOnLink on;
         AdvAutonomous on;
     };
     route 200::/7 {};
};