There are two ways described here to publish IPv6 ports from root started podman containers.

• Add --network slirp4netns:port_handler=rootlesskit e.g.

sudo podman run --network slirp4netns:port_handler=rootlesskit -p 8080:80 docker.io/nginx

• Create an IPv6 private network for podman

sudo podman network create --ipv6 --subnet fd01::/96 ipv6
sudo podman run -d --network ipv6 -p 8080:80 docker.io/nginx