Stitch Facebook authentication returns "AuthError"

Using the Stitch Facebook authentication provider with the Web/JS SDK the auth flow seems to work fine up until the redirect is done back to the Stitch servers.

loginFB() {
  const credentialFB = new FacebookRedirectCredential();
  this.$stitch.auth.loginWithRedirect(credentialFB);
} 

It then returns this error from the Stitch service:

https://eu-west-1.aws.stitch.mongodb.com/api/client/v2.0/auth/callback?code=AQClGc41QMShUyLT0FOIyGM4ZEi8FPEj4qSHF022F6gGqdIYrgBmop7QVWVuKQYH-CNCtGNSpOWJSVu9_nZwrHauMVrKt6CeswVIgRs5iQpt84YPFkg35BXZHf_PGcpvTsTBt2HC4B_yyYCcYCc4Ccn_wlCkG9bu-LwfKOePDtTYOJahys-xflBC8IyveMZIAK9lc00orXqC7zooETDgrE8KdoDw6uE8Q8zT_XMD7fGmCB7_-kcnmE9wScgC2Vsb38_AG4dkazNG_IenKpbo0s7vfDDfRLPawXpeWpSue_PRYLGSoKUB1UyWSNiujuq3ClE&state=nBspwBNKIdbEUxcyFdrHDudGKbuJhfjVTcHpzyMjSi-uImn5LQG3XtsgqRUGsB_UIEVnAIi6dswt5FwV90kphQ%3D%3D#=

error: "error exchanging access code with OAuth2 provider"
error_code: "AuthError"
link: "https://stitch.mongodb.com/groups/5ded6422f2a30b6096c347b8/apps/5dfdd120fab085de276dacb2/logs?co_id=5e176295f9d51cd518d60dc6"

Following the link in the error message we arrive at the Stitch logs which says the same thing.

I have followed the official docs (Google Auth works wonders, no worries there) for setting it up and tested the following:

• Modified Redirect URIs, tested on hosted (https / http) and localhost.
• Configured a Test App in Facebook dev
• Tested the various settings for the auth in Facebook console.
• Enable forced Re-auth in Facebook, I must then provide password and once that completes same error.

Trying to find information on this error in the official docs or here on Stackoverflow has yielded no results unfortunately. Could someone help explain how to get around this error?

Docs: https://docs.mongodb.com/stitch/authentication/facebook/

https://docs.mongodb.com/stitch/tutorials/guides/todo-guide-facebook/

The error shown was due to a faulty app secret in the Auth provider section in Stitch. Once that was mended to a correct secret from the Facebook App the login worked as intended. This error should be mentioned somewhere in stitch docs but does not to be documented there at the time of writing this.