URL duplicated so pages won’t load

Hello,

I am using this plugin to provide a login for customers. We are now experiencing a problem: when logged in and attempting to navigate to one of the sites pages it fails to load as the URL is incorrect. My website is driphacks.com. If I click on a page, the url suddenly changes to driphacksdriphacks.com and obviously leads nowhere.

Does anyone know how I can fix this?

Thank you!