Ubuntu and encrypting ed25519 keys

Good evening. Can anybody think of a reason Ubuntu would encrypt rsa keys, but not ed25519 keys at generation time?

ssh-keygen -t ed25519

Goes through the process, asks for a passphrase, and then does not encrypt the private key.

ssh-keygen -t rsa

Goes through the process, asks for a passphrase, and does encrypt the key.

My OpenBSD server won't do passwordless logins with a key that isn't encrypted and I'd like to use ed25519, if possible.

So I guess it's actually a problem between Ubuntu and OpenBSD. I can login from another OpenBSD machine no problem, but not from Ubuntu. I'm sure it's some kind of configuration mismatch or something. Any ideas?