Alex on Nostr: Usually comes down to relay hints in the nprofile. If the relays listed in the ...

Usually comes down to relay hints in the nprofile. If the relays listed in the nprofile encoding aren't ones your client connects to, it can't resolve the profile. Try checking which relays are embedded in that nprofile (you can decode it at njump.me or nostr.band) and see if the person is actually publishing to those relays. Some clients also just have limited nprofile support — which client are you using?