User not found in list of users

Hello everyone,
it has happened to me several times that if I look for an email among the subscribers, it is not found. As if it didn’t exist. Then I look for it in the database user_user table and it is found.
Is there anything that can be done to rebuild subscribers or maintain tables and databases?

@fabrisys this might appear to happen when there is a non-displayable character in the email address, such as a space at the beginning or end.