I'd be surprised if it were a different key from the regular host key.

Most SSH clients I know show a big and often non-overridable warning in case of a changed host key and don't allow (at least not TOFU-style) trusting two keys.

  > Most SSH clients I know show a big and often non-overridable warning in case of a changed host key and don't allow (at least not TOFU-style) trusting two keys.

You can solve this with HostKeyAlias, but yeah I doubt Apple would do this. Considering other comments mentioning "just SSHing after reboot" it's certainly the same host key.

  https://stackoverflow.com/questions/733753/how-to-handle-ssh-host-key-verification-with-2-different-hosts-on-the-same-but

PS: Another option obviously UserKnownHostsFile, but I would better keep single known hosts file.

Wow, TIL about HostKeyAlias and CheckHostIP. Especially the latter sounds super useful when it comes to frequently changing private IPs. Thank you!