nostr:npub16c0nh3dnadzqpm76uctf5hqhe2lny344zsmpm6feee9p5rdxaa9q586nvr on setting the lightning address, sounds their issue. 

You currently can't fund a mutiny lightning address from primal because they use strike in the backend for lightning and they have an issue where they can't pay to federations. Should hopefully be fixed soonish from what we hear.