Oauth authentication

I am trying to connect Formlift to Infusionsoft via oauth and I have setup the Infusionsoft developer app and a WordPress site solely as a proxy using the proxy plugin. I have this issue where when I try to connect Formlift to Infusionsoft I get directed through the authentication sequence properly, prompted to login at Infusionsoft, then authorize the developer app but then the callback URL is not redirecting properly back to the Formlift settings page with the token but ends back at the Infusionsoft account central page.
I realize that probably more information is needed to fully troubleshoot but wondered if this was a scenario that others have encountered and what the possible remedy is. Thanks in advance.