I got exactly the same issue today. I deactivated the plugin since the documentation said that it will restore to the old state. But it did not. I deleted the plugin from the dashboard and it was still the same. I wonder whether there is a conflict with the rename wp-login.php plugin which is active on my site. However, I do not dare to deactivate it, since it may block all access to the dashboard. Are there any suggestions for this? Thanks in advance.