nostr:npub1cdak4q4f3h3k3sgyh0rd5dj4w8k95f3mquzh6z3ew76vqkh60e3slyczgz That is because his follower hasn’t federated with the Fediverse server where your account lives.
Discussion
i see... so much hassle federating w/ one another, this is why #nostr is better 😉