OpenID-connect infinite redirect when using signup button

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1

Hi, I followed along with the great guide to using Auth0 with express. Then I duplicated the process in my own app. All was working well on my local machine. But now I have deployed to Heroku, and the signup button is leading to an infinite redirect loop after signing in.

Here is the url that shows in the browser:
https://auth0-security-jacynth.us.auth0.com/authorize?client_id=phT7xZVNOc5ZbaBSZXLnSeOyflDjIGce&scope=openid%20profile%20email&response_type=id_token&redirect_uri=https%3A%2F%2Fjacynth.herokuapp.com%2Fcallback&response_mode=form_post&screen_hint=signup&nonce=zW4FmpjD14r7t6-C0OktretPnZxbbsZWxPOqE9qDv2A&state=eyJyZXR1cm5UbyI6Ii9hdXRoL3NpZ24tdXAifQ

Here is the code for the sign-up route in my app:

app.get('/sign-up/', (req, res) => {
  res.oidc.login({
    authorizationParams: {
      screen_hint: 'signup'
    }
  });
});

Any idea what’s causing the problem?