Lock for Web with Facebook on Android device fails

Hello,

I’m having an issue with Embedded login using the Lock for Web SDK on an Android phone. The username/password flow seems to work as intended, but when logging into Facebook one of two things happen:

  1. If the user selects “open with chrome” for the facebook authorization step, it will redirect to Facebook, they’ll accept, and then are redirected to the auth0 callback on the custom domain that we have setup (https://custom.domain.com/login/callback?code=…). This page is completely blank. When I inspect the Android phone with remote debugging, there’s a message in the console Uncaught can't find relay frame. If I inspect the logs in Auth0’s UI, it says that the login was successful. This makes me think that something broke on the custom domain hosted by Auth0, and the login succeeded but the redirect back to my app broke.
  2. If the user selects “open with facebook app” for the facebook authorization step, it will redirect to Facebook, they’ll accept, and then is redirected to the same auth0 callback on the custom domain (https://custom.domain.com/login/callback?code=…), but this time I get an Oops!, something went wrong page from Auth0. The error message indicates that I “may have pressed the back button, refreshed during login, etc”. The logs in Auth0’s UI seems to indicate the same error occurred.

This is all very strange, as logging in on the web or on an iPhone seem to not have issues with Facebook. I also can’t exactly debug the network requests happening as the Facebook app opens because it leaves Chrome and I can’t inspect it.

Thanks, and let me know if there’s any additional information I can give. I did my best to search for related issues but nothing explains the issues I am experiencing.