Password expires for service account that uses SSH keys

Have a service account that has SSH keys generated for it.

It was having an issue trying to log in and once I unlocked the account and changed the password, it can log in now ok.

I couldn't find anything in Red Hat documentation showing this or talking about this. I looked online and this must be a Red Hat security feature as there are other Linux distros that allow for an account to sign in via SSH keys, even if the account is locked.

thanks