I've told that keyserver.pgp.com don't accept cv25519 key, but I've one of those key that also keyserver.ubuntu.com reject.

Then, I've also discover that Kelopatra allows you to create keys using usernames of only three letters, but the same keyserver that Kleopatra relies on rejects them.

However, I don't think I've seen a specific git for kleopatra to report this problem.