It looks like the Oracle container is relying on DNS resolution for gen-ai-labs-hub, but it's not resolving properly despite being in /etc/hosts. With --network=host, the container uses the host's network, but sometimes containerized processes can't read /etc/hosts correctly. Try setting the hostname explicitly with --hostname gen-ai-labs-hub in your podman run command — that often resolves this Oracle Net Listener issue without changing network modes.