I'm the Manager. I added their name and email address, and it shows as Pending. They got the email with the link to sign in. So far, so good. But we can't figure out how they create a password for their account.They're seeing a regular login screen, not one where they can enter a new password. Should they click on Create Account? That looks like it goes to create an entirely new Lastpass account, not a sub-account within my Family account.
If it matters, this name/email was a Family member. Due to forgotten/unrecoverable password I deleted them and added them again as a new Family Member.