Sign In with Apple Error: "Error from Apple Connection: (no description) (invalid_client)”

When creating an Apple Social Connection with generated Apple Keys and settings (as opposed to Auth0's dev keys for testing), the app seems to fail to authenticate with the following error:

Error from apple connection: (no description) (invalid_client)

A Failed Login may be seen in the Auth0 dashboard, similar to this:

• Apple Social Connections

This error can manifest if the Apple Team ID or Client Secret Signing Key set in the Auth0 dashboard for the Apple Connection is inaccurately configured. 

Confirm that the Apple Team ID and Client Secret Signing Key are the correct values received from Apple. In some cases, this may require revoking and creating a new secret key in the Apple Developer Portal, then updating the 'Client Secret Signing Key' in the Auth0 dashboard for the Apple Connection.