Unable to verify authorization request state.

I have not changed anything in my original set up (which worked up until last week). My auth0 strategy is as follows:

	// Perform the login
	app.get('/login',  passport.authenticate('auth0', {
	    clientID: env.AUTH0_CLIENT_ID,
	    domain: env.AUTH0_DOMAIN,
	    redirectUri: env.AUTH0_CALLBACK_URL,
	    audience: env.AUTH0_AUDIENCE,
	    responseType: 'code',
	    scope: 'openid profile'
	  }),
	  function(req, res) {
	    res.redirect('/');
	  }
	);

When a user goes to log in, they will be sent to the Auth0s authentication screen.

It lets me successfully log in to an account, however upon returning to this function:

	app.get('/authenticate', passport.authenticate('auth0', { failureRedirect: '/' }, ), 
		function(req, res) {
			console.log('called 4');			
	  	}
	);

The failure re-direct is ALWAYS called. Even though when I check my account, it reports that a successful log in has happened.

So I added the custom call-back to the above function like so:

    app.get('/authenticate', passport.authenticate('auth0', function(err, user, info) {
        console.log("authenticate");
        console.log(err);
        console.log(user);
        console.log(info);
    }, { failureRedirect: '/' }, ), 
		function(req, res) {
                    ...
	  	}
    );

Which now gives me the response:

authenticate
null
false
{ message: 'Unable to verify authorization request state.' }

What does this mean? I cannot find anywhere on the documentation or the community posts that states that on an average authentication method I would need to add a request state.