Just thought I would add some more info for clarification:
– When I first put in the URL above and I am logged out of WordPress, the login screen appears successfully
– My username and password are accepted in the login screen, I can tell this because if I open a new tab and enter the direct link to wp-admin I am logged in
– The URL above stays in the addressbar after clicking the login button, so the white screen is still on the WordPress site with the Oauth server pluing installed, not on my rest api client page.