Hi there,
Now I’ve got the idea about your issue. Basically we offered administrator only to visit the site as we block other roles to enter into the dashboard. In that case what you can do is disable that code snippet to enter into the site. Can you please provide a ftp access to your site so that we can disable that role redirection to frontpage from admins to other roles also. We can make it redirect only for customers or suppliers according to your needs. Let me know if you can provide the access or not.
Regards