If you created a new site by duplicating an existing site, the new user default settings will not carry over to the new site.
If a user is created on the actual site (not in the admin area of Pressero), the user will not be a member of any site groups. The user will not be able to see any products until you add the user to at least one site group. You will need to set the new user defaults in order to prevent this issue.
To do this, go to Admin> Sites > [site name} > User Management > Site Users >click on the settings icon > Click on "Edit New User Defaults" to expand this section. You can set the new user defaults to your preferences. Click "Save Defaults."