Does the 'Forgot Password' function work for users who's passwords have expired?

Summary:

We have a number of users that the Forgot Password function isn't working for. I'm trying to determine if this is expected behaviour for users whose accounts aren't locked but that their passwords have expired.

Content (required):

We have a number of users that the Forgot Password function isn't working for. I'm trying to determine if this is expected behaviour for users whose accounts aren't locked but that their passwords have expired. And are there any other circumstances that would cause the Forgot Password (and indeed the 'Automatically generate password' function on the Security Console for certain users) not to generate an email to the user? The issue isn't affecting all users, so I'm just trying to understand the expected behaviour of this function.